ANS 415 Final Exam

Typically a band of sheep will be consist of how many animals??

1,000 sheep and a bit more

Mink and Foxes are used for fur production, they are by nature??

Carnivores

Auto-Enzymatic Animals

Non-ruminants

Alloenzymatic Animals

Ruminants

In correlation to Leptin hormone, we can affirm that?

The main action is the regulation of feed intake

What is the ZONE OF THERMONEUTRALITY?

The metabolic rate of an animal is at a minimum

If a cow produce 38 kg/day of milk, and knowing that milk content of protein is 3.2%. How much protein should be provided per day,just to meet the milk requirements??

around 1,200-1,300 g

Due the high content of water in the milk, dairy cows have a big demand for water every day. How much percent of water we can expect to find in a regular milk?

around 85%

Lamb should receive colostrum after born. When the newborn should receive the colostrum??

first hour after born

Talking about high levels and the richness of this ingredient in the diets of rabbits, and knowing that rabbits are not very well adapted to that ingredient, and digest it very poorly. What kind of major ingredient in that in the feed I am talking about ?

high fiber levels

Because Methane has to be eliminated from the rumen by eructation, this represents a loss in energy, that loss can be around which value??

10%

How much should be a percentage of total protein content for maintenance in the rabbit diet?

12%

Respiratory Quotient (RQ)

the volume of CO2 produced when the respiratory substrate is respired, dividing by volume of oxygen consumed, in a set period of time RQ gives an indication of the respiratory substrate being respired and whether respiration is aerobic or anaerobic

What is the advantage to feed Beef Cattle with grains??

will reach slaughter age earlier, will be feasible to feed due low cost

If I have 10 grams of glucose, 10 grams of protein, and 5 grams of lipids, how many grams of metabolic water can be produced during the metabolism of these amounts of nutrients??

15.2 grams of water

How much nitrogen (%) can be found in 100 grams of protein??

16%

Water: Sources to Animals.

- Free water; 70 - 97% of the water consumed by the animal - Water from food; Intake of the water with the food, big variation. - Grains: has around 9 to 30% of water; - Pastures - Hay has less than 10% of water; - Fodder - has around 65 to 75% of water - Metabolic water. Result of oxidation of organic nutrients in the tissues; - Water is produced by chemical reactions in the cells. Each gram of Glucose can produce 0.6 grams of water. Glucose = 0.6g of water / 1 g of glucose (60% water); Protein = 42% Lipids = 100%

Phosphorus functions

- Is part of the bone matrix - Is part of the nucleoproteins, phospholipids, and nucleic acids (important in the growth) - Participation in acid-basic intracellular homeostasis - Part and activation of the coenzymes (NAD, and NADP) - Is extremely necessary in the metabolism and growth of rumen bacteria (Celluloliticas)

bomb calorimeter.

Determines the caloric content of biological materials • In brief, the sample is burned in a combustion chamber (bomb) inserted in a vessel containing a known weight of water. • As the sample burns, it releases heat, which is taken up by the water. • From the weight of the sample, weight of the water, and rise in temperature of the water, the number of calories of heat energy released can be calculated. • When a feed sample is burned in a bomb calorimeter, its gross energy is determined. • To determine the fraction of the gross energy that the animal can actually utilize, a metabolism trial must be conducted to account for various losses, yielding values for digestible, metabolizable and net energy: Digestible energy (DE) = Gross energy (GE) - Faecal energy. Metabolizable energy (ME) = DE - (Urinary energy + Rumen gas losses). Net energy (NE) = ME - Heat loss

The denomination, Type1, Type 2, Gestational, and Secondary are a reference to which disease???

Diabetes

How carbohydrates can be classified? Choose the correct alternative below.

Disaccharides, like sucrose and lactose

Pets animals are estimated to be around 100 million in the US, based on that is true to say?

Fish is the most numerous pets in the US

About Hibernation, mark the correct answer?

Hibernation is a behaviour to avoiding winter-feed scarcity

In the same order below, classify these animals according to the place where digestion or fermentation occurs, based in the classification of Foregut or Hindgut fermenter. RABBIT, HORSE, COW, DOG, SWINE

Hindgut, Hindgut, Foregut, Foregut, Foregut.

HindGut Fermenters

Horses Rabbits Ostrich

About the population of dogs in the US, we can affirm that?

In Washington State, dogs are more popular than cats.

Swine

In the first half of the twentieth century, most swine in the United States were raised in outdoor systems on pasture and supplemented with concentrate feeds. • Pasture and insects made a significant contribution to their nutritional needs, and sunshine provided adequate vitamin D activity • During the 1960s and 1970s there was a rapid shift to "complete or total confinement" production of swine, mainly for size economics and management considerations. • Most swine are now raised in complete confinement systems, except for a recent interest by a number of producers to produce "organically grown pigs" outdoors for a niche market. • Confinement reared pigs are totally dependent on the rations provided, without any opportunity to obtain nutrients from pasture or other sources for their total life-cycle nutrition. • In swine diet formulation, the nutrients or nutrient categories of most concern are energy (DE or ME), the limiting essential amino acids, calcium, phosphorus, trace minerals, and vitamins. • High-energy diets based on grains (usually corn) are used. • Because nutrient requirements vary with age, gender, and productive function, it is desirable to alter diet composition for different stages of the life-cycle from weaning to slaughter weight.

When a fur-bearing animals are fed with marine-fish, these animals can develop some deficiency of a specific mineral, and this can cause alteration in the fur quality. Which one is that mineral?

Iron

In the alternatives below, mark one that just has essential amino-acids

Isoleucine, Leucine, Lysine

In birds, when a corn -soy diet are used, which one is the first limiting amino-acid ?

Methionine

Some research data correlated with amino-acid requirements to Mink and Foxes, for fur production, have been show that there is a limitant amino-acid in the fur development. Which one is that amino-acid?

Methionine

Sulfur amino-acid donors sources should be increase wool production according of researchers from Australia. Which amino-acids we should supplements in the diet to increase wool production in sheep?

Methionine

In dairy cows, two amino-acids have been identified as a limitant for milk production, which AA are this?

Methionine and Lysine

Symbiotic Relationship between Ruminant and Microbes

Microbes provide to ruminant: digestion of cellulose and hemicellulose provision of high quality protein production of VFA provision of B vitamins detoxification of toxic compounds Ruminants provide to microbes: Housing Garbage removal Nutrients Optimal Environment for Growth

Minerals

Mineral elements are the inorganic components of plant and animal tissues. In animal nutrition, they are classified in two categories: Macro-minerals; Micro-minerals or trace Minerals • Sodium, Potassium and Chlorine are involved as electrolytes in regulating fluid balance between the gut, blood, cells, tissue spaces and body cavities. • Sulfur as such is not a dietary essential, but is a component of many organic constituents of tissue such as the sulfur-containing amino acids, the vitamins biotin and thiamin. • Mucopolysaccharides such chondroitin sulfate, and the metabolically essential coenzyme A (CoA) Other elements regulate enzyme activity, either as integral components of enzymes or as cofactors. As examples: Selenium as an integral component of the enzyme glutathione peroxidase Copper as a cofactor of cytochrome oxidase. There are other minerals like, Vanadium, Silicon, Boron, and Nickel, for which dietary need has been demonstrated only in laboratory animals fed with purified diets.

In the rumen fermentation, are included the synthesis of all of these components, except

Minerals

In the rumen fermentation, are included the synthesis of all of these components, except?

Minerals

How much does the rumen hold?

40 gallons >1,000,000,000,000,000 (1 quadrillion bugs) 1 milliliter of fluid = 100 billion bacteria + 10 million protozoa + 10 thousand fungi

The NRC has a recommended allowance of protein requirements to cat and dogs, based in g/1000 kcal, these values are respectively?

50 and 25 g

Ewes that delivery twins, should produce more milk then ones that just delivery one lamb. In twin delivery, the increase of milk production from these ewes should be around?

50% more

The Kjeldahl procedure can measure nitrogen. After knowing the amount of nitrogen in the substance, this will be multiplied by a factor to estimate the content of protein in the substance. How much is that factor??

6.25

Knowing that a dog of 40 lbs will need around 40 ounces a day of water, and a cat with 10 lbs will need around 10 ounces of water a day. If a person have a dog with 50 lbs and 2 cats weighting each one 12 lbs, how much water should be the minimum available to these animals every day?

74 ounces

The mineral Selenium and Vitamin E, plays an important role in the immune response defense in the immunological system to protect the animal against a pathogen. Whats is the most activity action of this Mineral and Vitamin?

Both have a very good antioxidant activity in the tissues

Water intake, how much ??

Bovines: Dairy cow: 40 to 65 L /day, + 1.5 to 2 L/ for each liter of milk produced. Beef cattle: 8 to 9 L / 100 kg of body weight. Sheep: 3.5 to 4 L / day. Horses: 30 to 45 L / day, Work horse 60 L/ day Chicken: 2 times the amount of feed intake, special requirements in thermic stress. Dogs and cats: around 30-60 mL / kg BW / day

In dairy cows, the high incidence of "Milk Fever" is correlated of the metabolism of which ingredient in the dairy cows feed?

Calcium

Calcium and Phosphorus for Cats and Dogs

Calcium and phosphorus are macro-minerals necessary for the formation and maintenance of bone. • In addition, circulating concentrations of these minerals are involved in body metabolism. • Calcium and phosphorus toxicities and deficiencies are rare in companion animals today due to properly formulated commercial diets. • Calcium toxicity can occur in companion animals.

Calcium

Calcium is the most common mineral in the human body and essential for many metabolic processes • Increasingly, calcium is being found to be involved in processes of energy metabolism as well. • For example, calcium activates a regulatory protein, calmodulin, which activates ion channels and numerous enzymes.

Mohair

Mohair /ˈmoʊhɛər/ is a fabric or yarn made from the hair of the Angora goat (not to be confused with the Angora rabbit which produces Angora wool). ... It is considered to be a luxury fiber, like cashmere, angora and silk, and can be more expensive than most wool that is produced by sheep.

Vaccines cause autism

NO

About the faction of energy that animals can utilize, is it correct to say that?

Net energy is reduced in correlation to metabolizable energy due to heat increment

What is the major factor that regulates forage intake in herbivores?

Neutral detergent fiber

In the cellular metabolism of CHO, in Auto-enzymatic animals, three complex B vitamin are required, these three vitamins are?

Niacin, Thiamin, Pantothenic Acid

In the cellular metabolism of CHO, in Auto-enzymatic animals, three vitamins from the complex B are required, these three vitamins are??

Niacin, Thiamin, Pantothenic Acid

Protein, how to measure it in feeds ???

Nitrogen is measures by the Kjeldahl procedure, which is named after the Danish chemist who develop it. It is important to recognize that the crude protein procedure measures nitrogen. Thus, it not distinguish between highquality and poor-quality protein, or protein and non-protein nitrogen

Nutrients

Nutrients may be defined as dietary essential for one or more species of animals, implying that not all animals require all nutrients. Example: • Few species besides primates and the guinea pig have a dietary requirement for vitamin C. • Ruminants animals do not normally have a dietary requirement for B-Complex vitamins and amino acids Some nutrients can be in fact omitted from the diet if appropriate adjustment are made, and for a short period of time. There is not requirement for carbohydrates per se. While glucose is an essential metabolite in mammalian metabolism, it is not a dietary essential. Other products can be metabolized to produce energy. For minerals and vitamins, the requirements are unequivocal; they have specific metabolic roles which cannot be replaced by other nutrients.

What is Nutrition ???

Nutrition can be defined as applied biochemistry, and is commonly referred to as nutritional science Animal Nutrition has conventionally meant the study of nutritional needs of domestic animals, in contrast with human nutrition, which specifically targets humans.

KETOSIS is a very common pathology in ewes, that is caused by???

shortage of glucose

Why rabbits does cecotrophy?

to absorb some vitamin B

The Gizzard in birds have the function of?

Particle size reduction

Ruminants

Ruminants are mainly herbivores like cows, sheep, and goats, whose entire diet consists of eating large amounts of roughage or fiber. They have evolved digestive systems that help them digest vast amounts of cellulose. An interesting feature of the ruminants' mouth is that they do not have upper incisor teeth. They use their lower teeth, tongue and lips to tear and chew their food. From the mouth, the food travels to the esophagus and on to the stomach. To help digest the large amount of plant material, the stomach of the ruminants is a multi-chambered organ. The four compartments of the stomach are called the rumen, reticulum, omasum, and abomasum These chambers contain many microbes that break down cellulose and ferment ingested food. The abomasum is the "true" stomach and is the equivalent of the monogastric stomach chamber where gastric juices are secreted. The four-compartment gastric chamber provides larger space and the microbial support necessary to digest plant material in ruminants. The fermentation process produces large amounts of gas in the stomach chamber, which must be eliminated. As in other animals, the small intestine plays an important role in nutrient absorption, and the large intestine helps in the elimination of waste.

Pseudo-Ruminants animals have the stomach divided as:

Rumen, Omaso, Abomaso

The digestion of starch can start in the mouth in some animals, Which animal can do that?

Swine

In the alternatives below, mark one that just has monogastric animals.

Swine and Chicken

Volatile fatty acids in Allo-enzymatic animals are very important in their metabolism, the VFA's are the main source of?

The main source of energy for metabolism.

Water absorption

The movement of water in the TGI is passive transport*, meaning without the expenditure of energy. Always in the direction to keep the TGI content in iso-osmotic state

Autoenzymatic Digesters

The nutritional requirements of animals are greatly influenced by the nature of their gastrointestinal tracts. This influence is at least two fold as digestive physiology is closely linked to: (i) food selection and dietary strategies; (ii) the ability of the animal to obtain nutritional benefit from particular types of feedstuffs. Animals have evolved to occupy virtually all ecological niches, and in many cases have developed specialized feeding strategies. Domestic animal types include: • carnivores (cats); • omnivores (pigs, chickens); • herbivores (cattle, sheep, horses, rabbits). These feeding strategies can influence nutrient metabolism and requirements. For example, members of the cat family have an almost exclusively meatbased diet, and as a result have a substantially different protein and amino acid metabolism than other animals. Taurine is exclusively found in animal-based proteins. It is critical for normal vision, normal digestion, normal heart muscle function, to maintain normal pregnancy and fetal development, and to maintain a healthy immune system. Taurine is an essential amino acid in the cat. Frugivores (fruit eaters) generally have a dietary requirement for vitamin C (e.g. fruit-eating bat). They have lost the ability to synthesize vitamin C because it is normally present in adequate amounts in their diets. Autoenzymatic digestion refers to digestive processes carried out by enzymes that the animal secretes into the digestive tract (auto : self), These terms have been introduced by Langer (1986). Animal scientists have traditionally referred to: Autoenzymatic digesters as monogastrics or non-ruminants. These terms are unsatisfactory in some respects. All animals are monogastric (i.e. have one gastric stomach). Many animals such as the ruminants have a complex, compartmentalized stomach, but technically speaking, they are monogastric.

All alternatives below are water sources for animals, except?

The water originated from the sweat

In a simple sentence, how Auto-enzymatic digesters could be defined?

They produce the digestive enzymes in the body

In a simple sentence, how auto-enzymatic digesters could be defined?

They produce the digestive enzymes in the body

In the cellular metabolism of CHO, 3 vitamins from the B group are required. Mark the option that shows the correct 3 vitamins from B group that are required.

Thiamin, Niacin, and Pantothenic Acid

Sheep and Goat Diets

• Sheep and goats share a number of nutritional similarities and are often discussed together under the term "small ruminants." • These animals are very important in developing countries, because of their small size, feeding behavior characteristics, and low water requirements. • They are intermediate feeders, are more selective in their feeding habits than cattle, and more likely to consume browse. • Most of the information on nutrient requirements for beef cattle applies as well to the small ruminants.

Environmental Pollutants and Reproduction

• A variety of environmental pollutants have adverse effects on reproduction in wildlife. • They primarily exert their effects through modulating or disrupting the endocrine system. • Many mimic endogenous hormones in chemical structure. • Synthetic (man-made) chemicals that act as hormone mimics include organochlorine pesticides (DDT and its metabolites, endo-sulfan, toxaphene, dieldrin), polychlorinated biphenyls (PCBs), dioxins and a further variety of industrial chemicals. • Many of these endocrine-disrupting chemicals affect estrogen and androgen metabolism. • There is some evidence of declining sperm counts in humans that may be linked to environmental pollutants.

Rickets

• In growing animals, the primary sign of deficiency of calcium, phosphorus and/or vitamin D, is rickets. • Rickets is characterized by spongy, poorly mineralized bones, leading to lameness, fractures, misshapen bones and death.

About dog and cat pet food, we can say that the generic food is?

Lowest cost in the market

The development of the winter coat in fur animals, are due the action of an specific hormone. Which hormone is it?

Melatonine

Talking about reproduction cycles, which of these animals has a diestrus cycle?

Dog

One of the factors that can produce KETOSIS in Allo-enzymatic animals is the low production of ???

Propionate

Which one alternative can be a sign of Diabetes in the animal??

Thirst and hunger

Fat-soluble vitamins are??? Except.

Vitamin K and A

The content of proteins are:

• 50 - 55% of Carbon • 6 - 7% of Hydrogen • 20 - 23% of Oxygen • 12 - 19% of Nitrogen • 0.2 - 3.0% of Sulfur

CHO Digestion in Allo-enzymatic Animals

• Carbohydrate digestion in ruminants is largely the result of microbial fermentation in the rumen. • Fermentation is anaerobic respiration. • Dietary carbohydrates are fermented, mainly by rumen bacteria, and the absorbed energy sources for the animal are the bacterial waste products, the VFAs • They are also known as short-chain fatty acids (SCFA). • The three major VFAs are: - (i) acetic (C2); - (ii) propionic (C3); - (iii) butyric (C4) acids. • Others include lactic acid, valeric acid and branched-chain VFAs such as isobutyric and isovaleric acids. • As a generalization, ruminants meet their protein needs by digesting rumen microbes, while they meet their energy needs by absorbing the waste products (VFAs) of rumen bacterial fermentation. Rumen Fermentation of CHO • Bacteria, protozoa and fungi are the three types of rumen microorganisms (RMO). • They all have roles in carbohydrate digestion, although bacteria are the most important. • Bacteria secrete enzymes that split the bonds linking sugars together in oligosaccharides, and polysaccharides, resulting in the release of free sugars • These are taken up immediately by the bacteria, and metabolized as energy sources. • Because the rumen is primarily anaerobic, the bacteria cannot oxidize sugars completely to carbon dioxide and water (luckily for the ruminant!). • They excrete carbon fragments in the form of VFAs, carbon dioxide and methane (CH4 ). • Small amounts of oxygen may enter the rumen, as air swallowed during feeding. • Although oxygen is toxic to obligate anaerobic bacteria, it is quickly utilized by facultative anaerobes. Rumen Fermentation of Cellulose • Bacteria that produce cellulase are called cellulolytic bacteria. • They attach to fiber particles and the cell walls of fibrous plant material consumed by the animal. • There is little or no free cellulase in the rumen contents. • Cellulolytic bacteria invade the plant cells, and tend to digest them from the inside, which protects them from predatory protozoa. • Rumen bacteria tend to form consortia with a common feeding strategy, so that the end products of one organism are often the substrate for another. • Some of the common cellulolytic bacteria are Bacteroides succinogenes, Rumitiococcus albus and Ruminococcus flavefaciens. • The major VFA produced by cellulolytic bacteria is acetic acid (C2). • Thus high roughage diets result in a high molar proportion of acetic acid as a percentage of total VFA. • Rumen fungi have a role in fiber digestion. • They invade highly lignified mature plant fiber (e.g. straw) and aid in its penetration by cellulolytic bacteria. • At least four genera of rumen fungi have been identified: • Neocallimastix, • Caecomyces, • Pyromyces, • Orpinomyces Rumen Starch Fermentation • Starch is a major dietary constituent of concentrate-fed ruminants, such as dairy and feedlot cattle. • Starch-digesting or amylolytic rumen bacteria include Bacteroides amylophilus, Streptococcus bovis, Succinimonas amylolytica and Succinivibrio dextrinosolvens. • The rate of degradation of starch depends upon its source and feed processing method. • Most grains are processed in some manner for ruminant feeding with such techniques as dry or steam rolling, extrusion, popping and grinding. • Amylolytic bacteria attach to feed particles and starch granules. • They secrete amylase at the point of attachment, degrading starch to maltose and free glucose units. • Glucose and other sugars are taken up by saccharolytic (sugar digesting) bacteria, such as Bacteroides ruminicola, Butyrivibrio fibrisolvens and Selenomonas ruminantium. • Fermentation of the sugars occurs by glycolysis with production of ATP for bacterial metabolism. • The end product of glycolysis, pyruvate, is converted to VFAs, carbon dioxide and methane. • The major end product of starch fermentation is propionic acid End products of rumen fermentation • The main end products of rumen fermentation are microbial cell mass, gases, heat (the heat of fermentation) and the VFAs. • The main gases produced during rumen fermentation are carbon dioxide, methane and small amounts of hydrogen and hydrogen sulfide. • Rumen gas is typically about 65% carbon dioxide and 25% methane. • Methane in the rumen is a hydrogen sink. • The rumen is a reducing environment, with excess hydrogen. • One means of hydrogen disposal is the formation of methane. • Rumen methane production has several adverse consequences. • Because methane is eliminated from the rumen by eructation, it represents a loss of energy (about 10% of gross energy intake). • Methane is a 'greenhouse gas', which accumulates in the upper atmosphere, contributing to the 'greenhouse effect' and global warming. • Ruminant methane makes a small but significant contribution to the global methane pool

Zinc for Cats and Dogs

• Zinc has several functions in the body, including nutrient metabolism, maintenance of healthy skin, and immune function. • Zinc plays a critical role as a cofactor or catalyst in over 200 reactions in the body. • A dietary zinc deficiency will cause impaired growth, poor skin and hair coat, and impaired reproductive performance in dogs. • Growing dogs that are fed a cerealbased, low-quality pet food that contains high concentrations of antinutritional factors such as phytate, which will bind zinc and impede absorption, can develop a deficiency. • Zinc deficiencies and excesses in cats are very rare.

Osteoporosis

• a bone disorder, in which the bone mass decreases, although its mineral composition is normal. Osteoporosis is common in elderly women.

Function of the water to animals.

- Temperature regulation; - Transport of nutrients and metabolites; - Help in the digestion process and metabolism of nutrients; - Diluent factor to urea, and uric acid excretion; - Mineral homeostasis; - Catalysts in the biochemistry reactions in the body; - Hydrolyzes of proteins, lipids, and carbohydrates; - Special actions (vision, brain, articulation, etc.)

In correlation to DMI, what is a " Benchmark to evaluate the farmer nutritional program" in dairy cows?

2 lbs of milk/ 1 lb of DMI.

The energy levels in a typical rabbit diet are quite low, this levels should be around how much?

2,400 - 2,800 kcal/kg

How to Change hair Growth

A "cotton fur" pelt of a dark mink. The fur is white because of a diet-induced iron deficiency. Iron deficiency impairs the enzymatic conversion of tyrosine to melanin in the hair follicle. Iron is a cofactor for the enzyme involved. • Hair is composed of keratin, a protein with a high cystine content. • Keratin is a polymer of amino acids in a helical coil, where cystine forms sulfhydryl bonds between the coils giving the hair elasticity. Hairs consist of a central core of cells, the medulla, surrounded by the cortex. Hair cortex is covered with an outer layer of cells called the cuticle; the cuticle cells give water-repellent properties by overlapping like shingles. The medulla contains air spaces. The hair color is determined by its structure and the pigments melanin (brown, black) and pheomelanin (yellow, red). • These pigments are synthesized from tyrosine. • The conversion of tyrosine to melanin involves an enzyme, tyrosinase, which requires copper and iron as cofactors. • White hair results both from a lack of pigment and reflection of light off the intercellular air spaces. • Other factors affecting hair color include cuticle structure (rough or smooth) and the degree of glossiness produced by sebaceous gland secretions. • Feeding sources of unsaturated fats, such as vegetable oils, increases sebaceous gland secretion and produces a glossy hair coat.

What is the best definition of RESPIRATORY QUOTIENT?

A CO2 produced / by O produced

What are ADF and NDF in forages?

ADF is a measure of the plant components in forages that are the least digestible by livestock, including cellulose and lignin. ADF increases digestibility decreases, so forages with high ADF concentrations are typically lower in energy. A plant's structural components are the source of NDF, specifically the cell walls. NDF relates to free-choice by livestock because it provides lowcalorie filler. You generally want to choose forages with low NDF percentages because these levels increase as forages mature.

In the foregut fermenters animals, the gastric stomach is?

Abomaso

The main digestive function of the hindgut is?

Absorption of water and electrolytes

The major VFA produced by Cellulolytic bacteria during the fermentation in the rumen is?

Acetic Acid

Vaccines are a good example of??

Acquired Immunity

In the metabolism of fat, the liver has a central role in that process, with the functions of?

All alternatives are correct

In correlation to the ways that animals can lose water, mark the sentence that is not correct.

All animals can lose around 80% of water with the skin evaporation mechanism.

alloenzymatic digestion

Alloenzymatic digestion (allo = other), in which digestion is accomplished in large part by enzymes produced by microbes inhabiting the gut.

Absorption of Amino acids

Amino-acids with a side chain non polar (Methionine, Leucine, Valine, Iso-leucine, Tryptophan, and PhenylAlanine) have a rapid absorption. Amino-acids with a side chain polar (Arginine, Glutamic acid, Aspartic acid, and Glycine) are very slow absorption. All others amino-acids (Histidine, Lysine, Alanine, Serine, Threonine, Tyrosine, Cystine, and Proline) have a intermediary speed of absorption. In general, proteins contain about 16% of nitrogen. The protein content of feeds is usually measured by determining the nitrogen content and multiplying it by the factor of 6.25. The crude protein is defined as N x 6.25 (16 g of nitrogen (N) come from 100 g protein; therefore, 1g of nitrogen is associated with 100/16 = 6.25 of protein).

Development of the nutrition

Animal and Poultry Nutritionist have played key roles in the development of the nutritional sciences. - Many species with different requirements; - Different physiological and anatomic characteristics; - Different growth due human interference; • On molecular levels, the similarities in metabolic process among animals are far greater than the differences, reflecting their common evolutionary history. • However, the passage of nutrients from the environment to the molecular level of the animal cells involves great species differences, largely because of differences in: • food selection; • food-seeking strategy; • digestive tract physiology; • digestive strategies.

Exotic Animals

Animal nutritionists may become involved in some aspect of the nutrition of wild or exotic animals. • Because wildlife specialists often do not receive much training in animal nutrition, professional animal nutritionists are a frequent source of information when questions arise in the wildlife field. • Wildlife researchers would "do well to obtain the cooperation in their experimental work of experts in animal nutrition. • Similarly, animal nutritionists might do well to have some knowledge of nutritional needs of wild animals. • Interest in zoo animal nutrition is increasing because it is widely appreciated that the high mortality rates of captive animals, which were once the norm, are no longer acceptable ethically and because of concerns about diminishing wild populations. • Much of the work on the nutrition of wild animals has been done with ruminants such as deer and many African species, as well as numerous African non-ruminant herbivores including the rhinoceros, elephant, and hippopotamus. • Considerable research has been conducted in Australia with marsupials such as the kangaroo, koala, and possum. • In North America, research has centered on the large ruminants (e.g., deer, elk, moose, and caribou). • There has also been considerable work on small herbivores such as the lagomorphs (rabbits and hares). • With zoo animals, research has emphasized the solution of such nutritional problems as mineral metabolism abnormalities in big cats and digestive disturbances and impactions in many herbivorous species, including concentrate- selector ruminants and arboreal monkeys. • Although the literature dealing with the nutrition of wild and exotic species is much less plentiful than for domestic animals.

Selenium Importance

Antioxidant action, participation in the selenium proteins • In animal production, the use of Organic selenium (seleniomethionine) reduce the mortality, improve feed efficiency, meat and milk quality. • Selenium is a key nutrient in animal nutrition and is crucial for an optimal antioxidant status and immune function.

Macro-Minerals:

Are required in relative large quantities; Calcium, Phosphorus and Magnesium are major components of the skeletal system, and thus function in a structural role. Macro-Minerals: exceeds 100mg daily Calcium, Phosphorus, Magnesium, Sodium, Potassium, Chlorine, Sulfur

If a cat diet does not have this nutrient in every meal, the cat can have episodes of vomiting, ataxia, and tetanic spasms. Which one is that nutrient?

Arginine

About the "Greenhouse effect", the Agriculture is accused to produce a lot of methane, around how much is this methane produced by agriculture?

Around 15%

Which one alternative below, in the past was referred to as a "Fertility Vitamin"?

Ascorbic Acid

Some frugivores animals lost in the evolution, the capacity to synthesize which vitamin?

Ascorbic Acid (Vit C)

Talking about the world production of Merino Wool, we can say that is true?

Australia is the biggest producer

Water soluble vitamin deficiencies

B6 - dermatitis, skin disorders, kidney stones, nausea, cracks at the corners of mouth B7 - nausea, vomiting, muscle pains, anemia, fatigue, loss of appetite, heart abnormalities B9 - deficiency of folic acid causes birth defects, anemia, diarrhea B12 - fatigue, anemia, neurological disorders, bone marrow C - improper healing of wounds, loose teeth, bleeding and swollen gums, muscle weakness

Ruminant Animal Examples

Beef and Dairy Cattle Goats Sheep Deer

Carbohydrates

Besides containing carbon, carbohydrates (CH2O)n , contain hydrogen and oxygen in the proportions found in water; hence the names (Hydrates of carbon). Carbohydrates are the basic energy source of almost all animal life. They are produced in the end of the products of photosynthesis by green plant tissue Photosynthesis is a very complicated process, but in simple terms, consist of the reduction (gain of hydrogen) of carbon dioxide in plants to produce carbohydrate. An input of energy is required. Plant tissue contains pigments, including chlorophyll and carotenoids (vit A precursors) that trap solar energy to provide electrons to accomplish the reduction of carbon dioxide Plants use the compounds formed in photosynthesis to synthesize all their other organic components such: • Amino-acids; • Sugars; • Starch; • Cellulose; • Lignin; • Lipids, and others When animals eat plants, the energy contained in the carbohydrates and other organic compounds, synthesized from carbohydrates (amino acids and lipids) is made available by metabolic process. Animal metabolism is in essence, the reverse of photosynthesis. Adenosine triphosphate (ATP) is the compound used in animal metabolism as the energy source for biochemical reactions. Animals are not capable of converting all of the available energy in carbohydrates to ATP, with a large part of the energy lost as heat • As these reactions indicate, plant and animals metabolism are symbiotically associate. • Plants require the carbon dioxide and water excreted as metabolic wastes by animals. • Animals require the oxygen excreted by plants and the organic compounds they synthesize. • The whole process is sustained by a constant infusion of solar energy. • Carbohydrates are the major dietary energy source for most of animals, with the exception of obligate carnivores. • They consist of two major types: • The starches, sugars and other ready available carbohydrates; • Cellulosic compounds which are more resistant to digestion. The readily available carbohydrates are associated with the plant cell content. The cellulosic compounds are constituents of the fibrous cell walls of plant tissue.

The Glycaemic / Glycemic Index

Carbohydrates that are digested slowly and release glucose gradually may produce metabolic effects that are different from dietary carbohydrates which are digested rapidly. • The glycaemic index measures the blood glucose response to a fixed amount of dietary carbohydrate compared to the same amount of a standard carbohydrate source, and thus measures the blood-glucoseraising potential of foods. • The blood-glucose area under the curve in a glucose tolerance test is expressed as a percentage of the standard. • The chemical nature of carbohydrates includes: - Type of monosaccharide (fructose and galactose have a lower glycaemic index than glucose), - Type of starch (amylopectin is digested more rapidly than amylose), - Presence of viscous non-starch polysaccharides (gums, Bglucans) which because of their viscosity reduce the rate of glucose absorption. - Foods with an intact botanical structure (whole grains) are digested more slowly than those with processed, gelatinized starch. • Cooking, processing and refining all tend to increase the glycaemic index.

Monogastric Animal Examples

Chickens Pigs Turkeys Dogs Cats

Which one is called a "Sunshine Vitamin"?

Cholecalciferol

Which type of fat could be the precursor of Vitamin D, Bile acids, Sex Hormones, and Corticosterone?

Cholesterol

Cholesterol Metabolism

Cholesterol is present either as free cholesterol or combined with a long chain fatty acid (LCFA) as cholesterol ester. • In plasma, both forms are transported with lipoproteins. • Cholesterol is amphipathic, meaning that it has both polar and non-polar properties, and thus is soluble in both water and lipid. • Because of this property, it is a constituent of cell membranes and the outer layer of lipoproteins. • All carbon atoms in cholesterol are derived from acetyl CoA. • It is synthesized in many tissues, particularly the liver, and is the precursor of all other steroids in the body (vitamin D, bile acids, androgens, oestrogens, corticosteroids). Cholesterol in the body is derived from both dietary sources and de novo synthesis in the liver and other tissues.

In rabbits, the excess of this vitamin can cause the mineralization of soft tissues all around the body, which one is that vitamin?

Colecalciferol

Autoenzymatic Digesters Immune Function

Colostrum Absorption Newborn animals of many species (Autoenzymatics and Alloenzimatics), large intact protein molecules are absorbed, permitting the absorption of antibodies from colostrum. This can be for several hours to several days, depending upon species. Guinea Pig = 1 day; Hamster = 5 days Rabbit = 23 days Immune function is another very important characteristic of the intestine that is not related to the digestive or absorptive functions. The gut has the body's major immunologic defenses, the gut-associated lymphoid tissue (GALT), including the Peyer's patches and the Bursa of Fabricius in chickens.

Ruminants Classifications

Concentrate selectors Concentrate selectors consume the less lignified (more soluble fiber) parts of herbage, including tree and shrub leaves, herbs, fruit and other soft, succulent plant parts. • This herbage, with a high concentration of cell contents and a low cell-wall content, is more readily digested than diets with similar total fiber but with more lignified and less soluble fiber. • A considerable portion of the material, such as starches and sugars, does not require fermentation but can be digested by the animal itself. • Although many concentrate selectors are small animals, such as the duiker, others such as deer, moose and giraffes are large. • They tend to nibble on a wide variety of plants and plant parts, rather than feeding intensively on one type of vegetation. • The larger concentrate selectors, such as deer and giraffes, consume the leaves and succulent foliage of trees, utilizing an ecological niche unavailable to grazing ruminants • Concentrate selectors have a stomach anatomy adapted to the use of low fiber forage. They have a relatively small rumen and reticulum, so cannot consume a large quantity of feed at one time. Grazers: • Roughage eaters or grazers have a feeding and digestive strategy based on the utilization of high- fiber, low-solubles diets. • Their stomach facilitates maximal digestibility of fiber. The capacity of the reticulo-rumen is high, and their grazing behavior permits a rapid intake of a large quantity of fibrous feed. • Rumination is pronounced, resulting in physical maceration of ingested forage. • The omasum is highly developed with many omasal leaves, thus retaining fibrous feed in the rumen until microbial enzymes have degraded it. • Examples of rough- age eaters include cattle, buffalo, camels and a variety of African antelope species. • A summary of some of the major differences in stomach anatomy and function between the roughage eaters and concentrate selectors. Intermediate feeders: • Intermediate feeders have feeding and digestive strategies that share properties of both concentrate selectors and grazers. • These animals tend to be highly adaptable to varying environments and changing habitats. • Sheep and goats are domestic animals of this type; they graze on grass but also feed extensively on shrubs and forbs. • Wild intermediate feeders include reindeer, elk, pronghorns, impala, gazelles and eland. Other ruminants: • The camels and other camelids (llama, alpaca, guanaco and vicuna) are considered to be ruminants, but have a substantially different stomach anatomy than other ruminants. The stomach has three compartments, roughly comparable to the rumen (C1), omaso (C2) and abomasum (C3). They are also called Pseudo-Ruminant

Sheep are the most susceptible livestock to the intoxication from this specific mineral. Which mineral is it?

Copper

Magnesium Importance

Correlated with calcium and Phosphorus, in the metabolism and distribution in the body. • Participation in the metabolism of carbohydrates, and lipids.

In the alternatives below, mark one that just has Foregut fermenters animals.

Cow and Alpaca

Nutrient Requirements for Pigs

Energy Requirements • Energy requirements for swine are expressed as digestible energy (DE) or metabolizable energy (ME), and the requirements for pigs from weaning to slaughter weight are shown in Table below (NRC, 1998). Values of ME are usually 94 to 97 percent of the DE. • The main energy source in growing-finishing swine and sow diets is usually starch from cereal grains. • Except for the neonatal pig, starch is completely digested in the small intestine. • Intestinal lactase production is high at birth, but pigs younger than 3 weeks have insufficient intestinal sucrase and pancreatic amylase secretion to digest sucrose or starch at birth. • The commercial availability of carbohydrate enzymes (e.g., (Betaglucanase) that increase the dry matter and energy digestibilities of barley and oats has made those grains more competitive for swine feeding. • In tropical countries, cassava meal and sweet potato meal are highenergy feedstuffs available for swine feeding. • In many developing countries, swine are fed grass and aquatic weeds (e.g., in China) and fibrous agricultural by-products. • The hindgut of the pig is relatively large, and microbial digestion of fibrous feedstuffs can be of significance. • When the crude-fiber content of the diet exceeds 10 to 15 percent, caloric intake may be reduced because of excessive bulk or reduced palatability • In general, pigs and other non-ruminants respond to diet dilution with fiber by increasing feed intake sufficient to meet their caloric requirements until gut capacity becomes limiting.

In the estrus cycle, which phase the female are receptive to the male?

Estrus

SPECIAL NUTRITIONAL CONCERNS WITH SWINE

Gastric Ulcers (esophagogastric parakeratosis) can be a significant problem in growing-finishing pigs. Damage to the stomach lining may impair digestive function or, in severe cases, lead to perforation of the stomach, peritonitis, and death. • Contributing factors seem to be stress (e.g., overcrowding) and the use of finely ground high-energy diets. • Such diets promote bacterial fermentation in the esophageal region of the stomach, and the organic acids produced cause irritation to the mucosa. • Oats and oat hulls tend to have protective effects by inhibiting gastric acid secretion. • Fibrous feedstuffs, in general, seem to have favorable effects in reducing gastric ulcers in swine.

The perception of food by visual or taste senses causes the liberation of 1 hormone in the stomach, which 1 is that hormone?

Gastrin

The perception of food by visual or taste senses causes the liberation of one hormone in the stomach, which one is that hormone?

Gastrin

These are functions of water to animals, except ?

Keep the heartbeat function

Which disease combination both are correlated with energy metabolism?

Metabolic Syndrome - Equine Metabolic Syndrome

Use the words below to complete the sentence. Ketosis is a _____________________________. Ketosis develops due the insufficient of __________________________. Ketosis in dairy cattle occurs in the early stage of ___________________________.

Metabolic disease, Glucose, Lactation.

In the Paleolithic diets, the majority of the food was?

Large feed intake of meat & fiber

Abnormalities of Bone

Leg abnormalities are a problem in poultry, especially in birds kept on wire. • Perosis, or slipped tendon is caused by deficiencies of choline and manganese. Perosis is due to an abnormality of the joint in the long bones of the leg, causing the tendon to slip and pull the leg sideways. • Cage layer fatigue is a type of osteoporosis that involves excessive mobilization of calcium from the leg bones, which causes the birds to have difficulty standing and broken bones. • It is primarily a problem with layers kept in wire cages at high stocking density. • Another leg disorder seen in broilers is tibial dyschondroplasia (TD) in which there is abnormal formation of cartilage in the long bones. • The cartilage forms a thickened layer below the epiphyseal plate. The lesion arises from the failure of growth plate chondrocytes to differentiate. • Dietary electrolyte balance and dietary alterations that affect acid-base or cation- anion balance have a role in TD

In the alternatives below, mark one that just has Herbivores animals.

Lhama and Cow

Glycemic Index Ratings

Low GI - <55 Medium GI - 56-69 High GI - 70>

Metabolic Syndrome is characterized by, except??? Mark the wrong answer.

Low blood cells count or Hyper-glycaemia?

Talking about Amino-acids, why Lysine is used to balance all other amino-acids in a diet? Mark only the wrong sentence.

Lysine is the most available amino acid in feed ingredients.

Talking about Amino-acids, why Lysine is used to balance all others amino-acids in a diet? Mark the wrong sentence.

Lysine is the most available amino acid in feed ingredients.

Which group of amino-acids are the main important in swine nutrition?

Lysine, Methionine, Tryptophan, and Threonine.

Two very important minerals are very required in Beef Cow production, they are?

Phosphorus and Calcium

Which offspring of birds can be considered altricials?

Macaw

Maintenance and Growth of Cats and Dogs

Maintenance • The majority of cats and dogs kept as pets today are in the maintenance state. • Maintenance is defined as an adult animal that is not pregnant, lactating, or working strenuously. • Animals in the maintenance state must be provided with a complete and balanced meal to meet their daily needs. • The main concern of the animal at maintenance is prevention of obesity. Growth • The most rapid period of growth for both dogs and cats occurs during the first 6 months of life. • During this time, body tissue is rapidly accreted and developed, and animals have increased energy and nutrient requirements.

How Autoenzymatic animals Digest

Mammalian species of this type, such as humans, pigs, dogs, cats, rats, mink and so on, have a pouch-like, noncompartmentalized stomach. Food is consumed, chewed and swallowed, moving down the esophagus into the stomach. Functions of the stomach include digestion and absorption, food storage and mixing, and secretion. The stomach of most autoenzymatic digesters consists of four functionally distinct zones The esophageal region is basically an extension of the esophagus. There are no glandular secretions in this region; there is some limited bacterial growth. The cardiac region, adjacent to the esophageal region, contains glands which exude mucus. The mucus, consisting of glycoproteins, has an alkaline reaction and serves to protect the stomach lining from being digested by the proteolytic enzymes and strong acid secreted into the stomach. The fundus gland and pyloric regions are the sites of other gastric secretions, including mucus, HCl and pepsin, a proteolytic enzyme. The HCl is not secreted preformed, but as hydrogen (H+) (derived from carbonic acid) and chloride (Cl-) ions which are secreted separately, forming HCl at the membrane surface of the secretory glands. The concentration of H+ ions in the stomach acid is about a million times greater than that of the blood. The energy required to secrete H+ ions across such a huge concentration gradient is derived from ATP. The high acidity sterilizes the stomach contents, killing virtually all bacteria consumed together with the food (diet). The low pH also has some digestive functions, causing some hydrolysis of proteins and polysaccharides, and denaturation of proteins, exposing the bonds of the amino acid polymer to further enzymatic digestion in the stomach and small intestine. It also activates the pro-enzyme pepsinogen, secreted by the gastric glands, forming the active proteolytic enzyme pepsin. lngesta exit the stomach from the pyloric region, entering the duodenum of the small intestine. Release of food from the stomach is controlled by the pyloric sphincter; it is regulated hormonally, so as not to overload the digestive capacities of the small intestine. Gastric secretions are controlled by gastrointestinal tract hormones, with the process initiated by the nervous system. A large number of gastrointestinal-tract hormones have been discovered. Perception of food by visual or taste senses causes stimulation of the vagus nerve, resulting in the release of the hormone gastrin from specialized secretory cells in the cardiac region. Gastrin is actually a family of polypeptides (big gastrin, little gastrin and mini-gastrin contain 34, 17 and 14 amino acids, respectively). Gastrin acts by regulating histamine production in gastric mucosa cells. Histamine in turn attaches to membrane receptors on the oxyntic cells of the gastric glands, activating cAMP. The cAMP activates carbonic anhydrase, producing H+ ions, and ATPase, causing secretion of Cl- in exchange for potassium (K+) ions. Gastrin secretion is also regulated by the intestine. Gastric inhibitory polypeptides (GIP) secreted from the small intestine mucosa initiate neural responses to inhibit gastrin secretion. Young animals (e.g. piglets) do not secrete pepsinogen, but rather secrete chymosin (rennin) which clots milk. Formation of milk clots is necessary to keep the immature small intestine from being overloaded.

Different Aspects of Digestive Tract Anatomy

Monogastrics, or Auto-enzymatics - Avian - Carnivores - Omnivores - Herbivores • Polygastrics, or Ruminants, or Allo-Enzymatics • Pseudo-Ruminants • Hindgut Fermenters

The main absorption of nutrients in Auto-enzymatic animals takes place where?

Most in the surface of the villi

Introduction to Comparative Nutrition

Nutrition is a very broad discipline, that include various aspects of : Biochemistry Physiology Endocrinology Immunology Microbiology Pathology Nutritional science deals with the principles of nutrition, while dietetics and diet formulation deal with their application. • There are similarities among wild avian species to domestic poultry, as well as numerous differences. • Digestive process in hindgut digester in wild animals: - Such as elephants, share some similarities with domestic species like a horse. - Whereas the koala resembles the rabbit in hindgut function.

Some animals can do the Caecotrophy, what is the main benefit of it to the animal?

Obtaining some Vitamin B that was excreted

Unsaturated Fatty Acid

Oleic Acid (C18 Monounsaturated) Linoleic Acid (C18 Polyunsaturated) Alpha-Linolenic Acid (C18 Polyunsaturated) Gamma-Linolenic Acid (C18 Polyunsaturated) Ricinoleic Acid (C18 Monounsaturated)

PETA and Fur

People for the Ethical Treatment of Animals (PETA) holds an anti-fur demonstration in Washington, DC, on June 21, 2011. They say "fur-bearing animals suffer when they're skinned alive, they also suffer during the summer months when confined to cages in extremely hot temperatures." UPI/Roger L. Wollenberg | License Photo

In correlation of lipid peroxidation, choose one alternative that is correct

Peroxidation occur when lipids are exposed to oxygen

The true gastric stomach in birds is?

Proventriculus

Calcium is correlated with, except?

Release of thyroid hormones to the blood

The mineral calcium is very correlated with, except?? Mark the wrong answer.

Release of thyroid hormones to the blood

DDT Damage

Reproductive Failure (in birds - eggshell thinning) Immune system problems Nervous system damage Death

The deficiency and toxicity of this specific vitamin can cause in rabbits some reproductive problems, this vitamin is?

Retinol

How Autoenzymatic Animals Digest 2

Since in young animals, the secretion of HCl is lower, and this makes the pH (3-5) in the stomach of young animals, allowing the colonization of the intestine with bacteria, and this can a problem. Acififiers (organic acids such as citric and fumaric acids) are sometimes used in diets for baby pigs, in an effort to avoid colonization of the gut with pathogens. Stomach Motility The motility is necessary to mixing gastric juice with the ingested feed, and for moving the digesta into the small intestine. Acidity is highest in the pyloric region. The esophageal region is little gastric acid, allowing microbial survival and growth in this area. Small intestine regulated the gastric motility, according with the capacity of the intestine to receive ingesta. The presence of unabsorbed lipid in the intestine also influences stomach emptying, mediated through the hormone Cholecystokinin. Ulcers in Stomach Pigs: are very susceptible to development of Ulcers. Carbohydrate fermentation by bacteria in the esophageal region Most cases of peptic ulcers are caused by a bacterial infection, specifically by Helicobacter pylori. H. Pylori survive the acidity of the stomach, due the secretion of urease, that after being converted to urea, and after break down in carbon dioxide and ammonia, neutralizes the acid in stomach. Digestion • Is the preparation of ingested nutrients for absorption. • Normally, only small molecules are absorbed. • Protein are hydrolyzed into small units (peptides and amino acids); • Complex Carbohydrates into simple sugars (monosaccharides); • Fat into mono-acylglycerides and fatty acids; • Minerals and Vitamins do not undergo digestion, and are absorbed as such.

Specialist Autoenzymatic Digesters

Some animals are specialist feeders, and have coevolved with particular plant species. Koalas and several other Australian arboreal folivores, have developed dietary preferences for eucalyptus foliage. It is difficult to raise koalas on any other diet except eucalyptus leaves, making their exhibition in zoos a challenge (although synthetic diets containing eucalyptus oil have been used successfully). Giant pandas are specialist feeders, consuming mainly bamboo foliage. Panda bear is a vegetarian carnivore; it is a member of the order Carnivora and has the dentition and digestive tract of a true carnivore but is vegetarian by feeding strategy).

Pseudo-ruminants

Some animals, such as camels and alpacas, are pseudoruminants. They eat a lot of plant material and roughage. Digesting plant material is not easy because plant cell walls contain the polymeric sugar molecule cellulose. The digestive enzymes of these animals cannot break down cellulose, but microorganisms present in the digestive system can. Pseudo-ruminants have a three-chamber stomach in the digestive system (C1, C2, and C3). However, their cecum—a pouched organ at the beginning of the large intestine containing many microorganisms that are necessary for the digestion of plant materials—is large and is the site where the roughage is fermented and digested. These animals do not have a stomach divided in 4 chambers like ruminants, but have an stomach divided in C1, C2, and C3 regions.

Talking about Allo-enzymatic digesters animals and lipids, how those animals metabolize lipids? (mark the correct sentence)

Some lipids can be very toxic to the rumen bacteria's

Talking about Allo-enzymatic digesters animals and lipids, how those animals metabolize lipids? (mark only the correct sentence)

Some lipids can be very toxic to the rumen bacterias.

In a cat diet, there is a specific free amino-acid that should be in the cat diet, if this is not included, the cat can be blind or have heart failure. Which free amino-acid is this?

Taurine

Which is the essential amino-acid that is needed to have in a cat diet in good amount?

Taurine

In the fur production industry, there is and state in the pelt that is considered to be in time to harvest, and they call it to be in "Prime Stage"? In which phase of the hair development this stage are reached?

Telogen phase

Is it true to say?

The African continent showed a higher growth rate in pet food market.

Hair Growth Cycle

The hair growth cycle. The growth of a new hair, or anagen phase (A), is followed by the catagen phase (B), during which the lower part of the follicle atrophies. Melanin pigments move up the hair fiber from the dermis to the epidermal area. When this occurs, the underside of the pelt changes from dark to white, indicating that the hair is prime (C, D). In the telogen phase (D), a new hair follicle is formed and a new hair begins growth (E), which causes the previous hair to be shed

Protein

The genetic control of protein synthesis involving DNA and RNA metabolism is one of marvels of life. Proteins are an integral part of animal structure and metabolism. They constitute a major part of the body structure, as components of muscle, connective tissue and cell membranes. All metabolic reactions are dependent on proteinaceous enzymes. Proteins are large molecules composed of amino acids joined together by peptide bonds. Plant and Animal proteins are composed of about 20 amino acids, arranged in various sequences to form specific proteins. A few other amino acids do not occur in protein tissue but have specific functions, and are known as noprotein amino acids (e.g citrulline). Animal nutritionist have to be careful to provide adequate dietary protein and amino acids in the feed formulations. In the comparative standpoint, there are great difference in protein utilization. Ruminants animals largely insulated from specific dietary amino acid requirements because of the activities of rumen microbes. Carnivores have some distinct differences from omnivores in amino acids needs

In the alternatives below, choose one that just includes a polar amino-acids?

Threonine

In correlation of Amino- acids, and Proteins, the limiting amino-acids are?

Threonine, Lysine, Tryptophan, and Methionine

In correlation of Amino-acids, & proteins, the limiting amino-acids are?

Threonine, Lysine, Trytophan, & Methionine

In the beef cow production farm, the calving interval is something very important for the farmer, why this is very important??

To be economically efficient each female should have one calf every year

With the nutritional insufficiency of this vitamin, birds can have encephalomalacia, & swine can show some exudative diatheses, which vitamin is that?

Tocopherol

Trace Minerals

Trace elements are required in very small amounts. The functions are primary in regulatory roles; Trace-Minerals: under 100mg daily Manganese, Zinc, Iron, Copper, Molybdenum, Selenium, Iodine, Cobalt, Chromium.

Fur can be in different colors. Which amino-acid is correlated which the color of the fur?

Tyrosine

About the stomach ulcers that can be caused by Helicobater pylori, this is due to the capacity of this bacteria to secrete

Urease

About the stomach ulcers that can be caused by Helicobater pylori, this is due to the capacity of this bacteria to secrete:

Urease

How the animals can lost water from the body?

Urine: • 15 to 21% of the intake water (feed and metabolic water); • Correlated with feed intake; • Correlated with environment, if is available or not; • Correlated with the content of K and N in the feed and urine; • Correlated with the dry matter of the diet (low DM% = high intake of Water). Feces: • Dependent of the intake of water; • Dependent of the % dry matter in the feed; • Succulent diets with high concentration of minerals = excretion of more water in the fecal matter; • Represent around 30 - 35% of the ingested water (free water and metabolic water). Skin Evaporation: • Very important way to lose water in the body, can be more then the urine excretion; • Correlated with physical activity; • Correlated with environmental temperatures; • Represent around 18% of the total water lost in the animal body Milk: • Correlated with around 30% of the total water intake ( free and metabolic water); • Milk has around 13% of solids, and 87% of water. Thermoregulation: Will be the equilibrium between the intake and the amount excreted. The ways to keep this balance will depend upon the animal specie, management, diseases, and dietary constrains associated with the animal husbandry. To be thirsty, is a result of increased concentration of electrolytes in corporal fluids. That is controlled by hypothalamus; Can be caused by : • Ambient temperature; • Water quality; • Diseases; • And others factors

These elements above can act as antioxidant in the animals' systems, except??

Vitamin A

The fat soluble vitamins

Vitamin A ( Retinol); Vitamin D (Cholecalciferol); Vitamin E (α-tocopherol); Vitamin K (Phylloquinone). Absorption: first into the lymph, then the blood Transport: may require protein carriers Storage: Stored in the cells associated with fat Excretion: less readily excreted, tend to remain in fat storage sites Toxicity: likely to reach toxic levels when consumed from supplements Requirements: needed in periodic doses (perhaps weeks or months)

The water soluble vitamins

Vitamin C (Ascorbic acid); Vitamin B-Complex : B1 (Thiamin); B2 (Riboflavin); B6 ( Pyridoxine); B12 (Cyanocobalamin); Niacin (Nicotinic acid, B3); Folacin (Folic acid, B9); Biotin (B7); Choline; Pantothenic acid (B5). Absorption: directly into blood Transport: travel freely Storage: circulate freely in water-filled parts of the body Excretion: kidneys detect and remove excess in urine Toxicity: possible to reach toxic levels when consumed from supplements Requirements: needed in frequent doses (perhaps 1-3 days)

Talking about vitamins, which one in swine nutrition can interfere with the blood clotting mechanism?

Vitamin K

These vitamins, normally don't need to be supplemented in dairy cows due the rumen fermentation. Which are the vitamins?

Vitamin from B Group, Vitamin K

Fat-soluble vitamins are???

Vitamins A, K, and E

Vitamins

Vitamins are organic compounds other than proteins, carbohydrates and lipids that have specific roles in metabolism, and are required in the diet in very small amounts. Deficiency causes a specific disease, which is cured or prevented only by restoring the vitamin to the diet. In most case, these roles are in regulation of enzyme function. As example: Vitamin K = Impaired blood clotting, due the enzyme role of vitamin K. Vitamin A = Deficiency can result in blindness. The term "Vitamin" was created in 1912 by Polish chemist, Casimir Funk. Vitamins can be classified in two groups: The fat soluble vitamins and the water soluble vitamins

DMI in dairy cows are very correlated with the intake of a special nutrient, which one is that nutrient??

Water

Why water is considered a nutrient.

Water for domestic animals does not fit totally the definition of a nutrient because it is not generally required in the diet (food) but it is usually consumed separately as drinking water. Some desert animals (e.g. pack rats) never drink, but survive on metabolic water. Marine mammals (e.g. seals, sea lions) never drink, but obtain their water from theirs diets (fish tissue), while fruiteating animals (frugivores) obtain a major portion of their water from the diets (fruits). For those animals, water is a nutrient. Water is the element more present in animals. 50 - 80% of the animal body ! Water content of: Chick - 85% Chicken - 55% Jellyfish - 96% Water content in Bovines Fetus 95% - Calf (New Born) 75 - 80% - At 5 Months (Calf) - 65 - 70% - Adult Bovine - 50 - 69%

Why in cold weather situation, the low-quality forage will be better choice to cows?

Will help to produce more heat in the rumen

About the emulsification process, we can affirm that: Mark one alternative.

With the help of emulsification and micelle formation monogastric animals can absorb the fat from diet

In the auto-enzymatic animals the acid pH in the stomach can help to?

all above are correct

In the auto-enzymatic animals the acid pH in the stomach can help to??

all alternatives are correct: Kill all bacteria consumed with the food Help to reduce the microorganism in the stomach content Causes the hydrolyzes of proteins Causes hydrolyzes of polysaccharides

Why is urea used in beef cow production?

can be a good source of nitrogen

Concentrate selectors animals are ones that prefer to eat? Select 1 answer.

consume plants high in starch, protein, & lipids

Concentrate selectors animals are ones that prefer to eat? Select one answer.

consume plants high in starch, protein, and lipids

Allo-enzymatic animals are those who:

digestion is accomplished in part by enzymes produced by microbes in the gut

Why is more difficult to evaluate the DE in cows??

due the losses of gas

In auto-enzymatic animals, the stomach is divided in:

esophageal, cardiac, fundus and pyloric regions

In a very efficient dairy farm, the calving interval should be at least?

one year

FEEDING AND NUTRITION OF SHEEP

• A high proportion of the diet of sheep is normally made up of forage. • One viewpoint of some sheep farmers is that they are actually forage farmers, and the sheep are merely a tool for harvesting and marketing the forage. • Lambs can be finished to a consumer acceptable market grade or end point without the need for a grain-feeding period. • Therefore, more than with other species, there is often an effort to maximize forage utilization by sheep and minimize the use of concentrate feed. • In North America, sheep production is a fairly minor economic activity. • Sheep numbers have declined markedly since the 1940s for a variety of reasons, including predator problems, lack of profitability compared to beef cattle production, decline in the value of wool, and decreased market demand for lamb. • New production techniques could reverse this pattern. • Most North American sheep production involves either farm flocks or range sheep operations. Range sheep production is located in the western regions. Range sheep are generally under the control of a herder and are grazed on semiarid desert lands and on high mountain ranges. • Typically, a band of sheep will consist of 1,000 to 2,000 ewes and their lambs. • Large sheep ranches may have numerous bands. • Farm flocks are kept in fenced pastures and generally involve no more than a few hundred ewes. • The ewes are kept on pasture or conserved forage (hay, silage) for most of the year. • Supplemental feeds are provided only in periods of nutritional stress, primarily in the period immediately before and after lambing. • With farm flocks, the lambs are usually fed on the farm until market weight is reached. • Range lambs are often marketed as feeders (lightweight lambs), which are fattened on concentrate feeds in feedlots or on irrigated pastures and crop residues.

Odor Control and Ecological Nutrition for Swine

• A major concern with intensive swine production is air and water pollution. • The problems involve excretion of nitrogen, phosphorus, and other minerals that may pollute surface and ground waters, and pollution of the air with ammonia and swine odors. • Aspects of ecological nutrition to reduce excretion. - For example, use of phytases as feed additives can increase phosphorus bioavailability and reduce phosphorus excretion. - Nitrogen excretion in the urine can be minimized by avoiding the feeding of excess protein and by using well-balanced diets that precisely meet amino acid requirements. • The odor associated with intensive swine production causes tremendous environmental problems. • Swine odors are offensive to people and can cause health problems. • More than 200 odorous and offensive compounds have been identified in swine manure and lagoons. • Many of the offensive compounds in swine excreta are derived from protein.

Preweaning Swine Diets

• A pre-starter diet is needed when baby pigs need to be removed from the sow and reared artificially because of sow lactation failure. • Pre-starter diets have a high protein content (22 to 24 percent) and must contain high-quality readily digestible feedstuffs such as spray-dried animal plasma, spray-dried skim milk, spray-dried whey, lactose as the carbohydrate source, and 1 or 2 percent fat as corn or soybean oil. • These ingredients are very palatable and digestible by the baby pig. • Because the baby pig lacks intestinal sucrase and pancreatic amylase activities at birth, sucrose (table sugar) and starch should not be added to a pre-starter or the first post-weaning diet to prevent digestive disturbances and diarrhea.

OTHER RUMINANTS Nutrition

• A variety of other ruminant animals, including the buffalo, yak, camel, and llama, are raised in various parts of the world. • Interest in llama production in the United States is increasing. • The animals are used as pets, for back-packing, as guard animals for sheep, and for wool production. • The llama and other camelids are sometimes called pseudo-ruminants because their stomach anatomy is different from that of the true ruminants. • There is little specific information on the nutritional requirements of llamas. • They seem to be similar to sheep in their feeding needs. • They also are compared the intake and digestibility of camelids (llama and guanaco) to sheep fed a lowquality roughage (ryegrass straw). • Per unit of metabolic rate, feed intakes were similar, but water intake of the camelids was approximately 40% less.

Energy Requirements of Dairy Cows

• After water, energy is probably the most important nutrient to provide for milk production. • Each kg of milk (corrected to 4 percent milk fat) produced requires approximately 0.74 Mcal of NFL (NRC, 1989). • The average cow in the United states in 8,441 kg of milk or 27.7 kg/d during the 10-month (305 day) lactation. 2002 produced • Therefore, this cow needed 20.5 Mcal of NEL /d or more just to meet the energy requirements for milk production.

Alloenzymatic Digesters

• Allo-enzymatic digesters are those animals in which digestion is accomplished in part by enzymes produced by microbes inhabiting the gut. • The site of microbial activity may be the: - foregut (e.g. ruminants); - hindgut (e.g. horses and other nonruminant herbivores).

Mineral Requirements of Dairy Cows

• Although they constitute a small proportion of most diets, minerals are rapidly becoming more important in dairy cattle nutrition as advances in our understanding of their biological roles. • Probably the largest impact of proper mineral nutrition is on the incidence of the metabolic disorder parturient paresis or milk fever. • Incidence of parturient paresis in dairy herds has ranged from zero to over 20%. • Calcium metabolism is the controlling factor for developing parturient paresis. • Abnormal Ca metabolism at or around parturition will predispose cows to developing the disorder

Protein and Amino Acids Requirements for Avian

• Amino acid requirements for poultry are somewhat different than for swine in that glycine or serine, which can be used interchangeably, are dietary requirements, and the arginine requirement is higher than for swine. • Both of these differences are related to mechanisms of nitrogen metabolism. • The bird lacks the full complement of urea cycle enzymes involved in urea synthesis and excretes uric acid as an end product of protein metabolism. • In mammals, urea for excretion is formed in the liver; in the final step of the urea cycle, a molecule of urea and a molecule of arginine are formed. • Conversely, in the formation of uric acid in the bird, glycine is required as it contributes part of the uric acid molecule, and the bird is unable to synthesize arginine. • Soybean meal is the major plant protein supplement used in poultry diets. • Cottonseed meal should be avoided in poultry diets, especially for layers, because of gossypol toxicity. • Because the protein and amino acid requirements as a percent of diet are higher for poultry than for swine, high-protein supplements such as fish meal are more commonly used in poultry feeding. • Methionine is the first-limiting amino acid in corn-soy diets for poultry. • Synthetic methionine is widely used as a supplement, either as DLmethionine or methionine hydroxy analog. • Whereas in the past most diets were formulated on the actual content of the amino acids in the feedstuff, there has been a shift toward formulation of diets on a digestible amino acid basis. • Digestible amino acids refer, to that portion of the protein that is actually absorbed by the birds, rather than excreted. • This is a more accurate form of expressing requirements, and should be used when sufficient data are available.

Amino-acids structure

• Amino-acids are organic molecules, that is composed of atoms of carbon, hydrogen, oxygen, nitrogen. • Some amino-acids also can have sulfur. • Amino-acids are divided in 4 parts: - Amino group (NH2), and Carboxylic group (COOH); - Hydrogen; - Alpha carbon; - Side chain (characteristic of each AA)

Mineral Requirements of Beef Cattle

• Calcium and phosphorus are the minerals required in greatest quantity by beef cattle. • Forage legumes are rich sources of calcium, and moderately good sources of phosphorus, whereas grains and grain by-products are good sources of phosphorus, but very poor sources of calcium. • Grasses are moderate to low, in both calcium and phosphorus content. • With pasture or hay-fed cattle, calcium supplementation is usually necessary only for lactating cows. • Phosphorus is particularly important in the postpartum period; cows with borderline phosphorus deficiency, may not have normal estrous cycles, and calving interval may be longer. • Specific trace mineral deficiencies occur in many areas, depending upon local soil conditions. • Selenium, copper, and cobalt deficiencies are practical problems in many areas.

Monogastric

• As the word monogastric suggests, this type of digestive system consists of one ("mono") stomach chamber ("gastric"). • Humans and many animals have a monogastric digestive system. • The process of digestion begins with the mouth and the intake of food. • The teeth play an important role in masticating (chewing) or physically breaking down food into smaller particles. Humans and herbivores, such as the (b) rabbit, have a monogastric digestive system. However, in the rabbit the small intestine and cecum are enlarged to allow more time to digest plant material. The enlarged organ provides more surface area for absorption of nutrients. Rabbits digest their food twice: the first time food passes through the digestive system, it collects in the cecum, and then it passes as soft feces called cecotrophes. The rabbit re-ingests these cecotrophes to further digest them. • The enzymes present in saliva also begin to chemically break down food (Amylase - starch). • The esophagus is a long tube that connects the mouth to the stomach. • Using peristalsis, or wave -like smooth muscle contractions, the muscles of the esophagus push the food towards the stomach. • In order to speed up the actions of enzymes in the stomach, the environment of the stomach is an extremely acidic, with a pH between 1.5 and 2.5. • The gastric juices, which include enzymes in the stomach, act on the food particles and continue the process of digestion. • Further breakdown of food takes place in the small intestine where enzymes produced by the liver, the small intestine, and the pancreas continue the process of digestion. • The nutrients are absorbed into the blood stream across the epithelial cells lining the walls of the small intestines. • The waste material travels on to the large intestine where water is absorbed and the drier waste material is compacted into feces; • It is stored until it is excreted through the rectum.

Avian Digestive System

• Avian (bird) species with auto-enzymatic digestion have some modifications from the mammalian digestive system. The stomach is divided into two compartments, the proventriculus (gastric stomach) and the gizzard (ventriculus). • In addition, between the beak and proventriculus is a diverticulum of the esophagus called the crop. • In domestic avian species, the crop functions mainly as a food storage area, although some microbial digestion may occur. • Mucus glands in the upper esophagus, secrete mucus, which aids in the movement of ingested feed to the crop. • In some birds, such as pigeons, doves, parrots, penguins, flamingos and pelicans, the crop produces 'milk' which is regurgitated into the crops of the young. • The milk consists largely of lipid- rich epithelial cells plus ingested feed. The production of crop milk is stimulated by the hormone prolactin. • The proventriculus elaborates HCl and pepsinogen in much the same manner as the mammalian stomach. • The ingesta then move to the gizzard, where grinding of the material occurs. • There is some refluxing of ingesta from the gizzard back to the proventriculus. • The gizzard performs the functions of mammalian teeth in grinding ingested material into small particles The major site of digestion and absorption in birds is the small intestine. The small intestine is divided in duodenum, jejunum, and Ileum. • Antiperistalsis occurs when the material is moved 'backwards' or in a retrograde manner; this occurs primarily in the hindgut as a means of moving material from the colon into the caecum. • This action is important in small herbivores, such as the rabbit. • In chickens, antiperistalsis occurs in the colon; digesta mixed with urine from the cloaca refluxes small particles (fines) and fluids into the caeca (Moran, 2006). • The colon has very little digestive activity, in chickens. • Some fermentation in the caeca occurs; reverse peristaltic contractions move fluids and fine particles from the colon into the caecum. • Some bacterial vitamin synthesis occurs, which is of nutritional benefit to birds that have access to their excreta and consume them (coprophagy). • In birds, the gastrointestinal tract terminates in the cloaca, into which the urine is also excreted, so that faeces and urine are voided together in all avian species except the ostrich, which excretes faeces and urine separately

Vitamin Requirements of Avian

• Because of the simple digestive tract and rapid rate of passage of digesta in poultry, there is little intestinal synthesis of B-complex vitamins. • Birds do not utilize vitamin D2 efficiently, so poultry diets should be supplemented with vitamin D3 . • Requirements of poultry for vitamin D are expressed in International Chick Units (ICU), based on the activity in chick bioassays. One ICU is defined as 0.025 mg of vitamin D3 . • Vitamin D is also available commercially in the hydroxylated form, 25 OH D3 . • It is absorbed more efficiently in this form than as vitamin D3 . • Use of the 25 OH D3 may help prevent skeletal deformities in young chicks induced by the fat malabsorption syndrome. • Vitamin E deficiency signs in poultry include nutritional muscular dystrophy, exudative diathesis, and encephalomalacia (crazy chick disease). • As in other species, the requirement for vitamin E depends upon the dietary selenium level, and the presence of synthetic antioxidants, which have a sparing effect on vitamin E. • Diets high in unsaturated fatty acids, increase vitamin E requirements. • Vitamin K is important in poultry nutrition because of the lack of microbial vitamin synthesis in the gut. • Signs of vitamin K deficiency are related to its role in blood clotting. • Mild deficiency, may result in small internal hemorrhages, that cause blemishes on the carcass. • Numerous outbreaks of hemorrhagic syndrome have occurred in commercial flocks

Diets of Beef Cattle

• Beef cattle are well adapted to the utilization of forages. • In the developed countries, there has been a trend in recent years to feed diets high in grain to ruminant animals. • Most beef cattle in the United States are finished in feedlots where they are fed diets high in grain, and low in forages. • Grains are usually the least expensive sources of DE for livestock in the developed countries, most of which have large grain surpluses. • In addition, because high-concentrate feeds allow full expression of genetic potential for growth, the time taken to reach market weight is much less in grain-fed animals, than in those fed forage. • Grain-fed cattle can reach slaughter weight at approximately 1 year of age or slightly more, whereas cattle raised on forage may take 1.5 to 3 years (or more on tropical pastures). • Therefore, the nutrient expenditure for maintenance needs is much less over the life time of the concentrate-fed animal, and the total number of animals that can be produced is greater. • Grain feeding is also used because of the widespread belief that the eating quality of the beef is superior, with grain-fed animals. • Concerns about the effects of animal fat on human health may result in a reduction in the amount of grain fed to beef cattle. • In the United States, numerous cattle producers are marketing "light" or "natural" beef from animals fed little or no grain prior to slaughter • Although raising ruminants on high - concentrate diets makes economic sense at the present time, it may not make sense in terms of optimal biological efficiency . • Non-ruminants, such as swine and poultry, can produce meat more efficiently from grain, than ruminants can, because they do not have the energy losses associated with rumen fermentation. • Second, the ruminant digestive tract has evolved to utilize fibrous feeds. • It seems intuitively logical, to feed ruminants the types of feeds to which they are best adapted, rather than the concentrate feeds that may induce a numeric metabolic problems (e.g., displaced abomasum and lactic acidosis)

Avian Digestive Tract

• Birds face special challenges when it comes to obtaining nutrition from food. • They do not have teeth and so their digestive system, must be able to process un-masticated food. • Birds have evolved a variety of beak types that reflect the vast variety in their diet, ranging from seeds and insects to fruits and nuts • Because most birds fly, their metabolic rates are high, in order to efficiently process food, and keep their body weight low The stomach of birds has two chambers: the proventriculus, where gastric juices are produced to digest the food before it enters the stomach, and the gizzard, where the food is stored, soaked, and mechanically ground. • The undigested material forms food pellets that are sometimes regurgitated. • Most of the chemical digestion and absorption happens in the intestine and the waste is excreted through the cloaca.

Energy Storage as body fat

• Body fat is stored as TAGs in specialized fat cells (adipocytes). • As with glycogen, body fat is mobilized or deposited in accordance with energy needs of the tissue cells, with these processes controlled by hormones. • Some of these include insulin, epinephrine (adrenalin), norepinephrine (noradrenalin) and adrenocorticotropic hormone (ACTH). • Insulin inhibits the catecholamine-stimulated release of free fatty acids (FFAs) from adipose tissue, and is a major regulator of adipose tissue metabolism. • A body weight regulatory hormone, leptin, stimulates lipolysis and inhibits lipogenesis by influencing the activity of enzymes involved in fatty acid synthesis and degradation. • The main influence of leptin is in regulation of feed intake. TAGs in adipose tissue undergo continual breakdown and deposition, regardless of the need for energy storage or mobilization (the dynamic state of body fat). • For this reason, and the lack of modification of dietary-derived fatty acids, the carcass fat of non-ruminant animals tends to resemble (in fatty acid composition) the dietary fat. • If a pig is fed a diet with mainly saturated fatty acids, its body fat will be saturated; if it is fed unsaturated fatty acids, its body fat will be unsaturated. • In the case of ruminants, the carcass fat tends to be more saturated, regardless of the diet. • Explanations for this include the biohydrogenation of unsaturated fatty acids in the rumen, and the fact that much of the body fat in ruminants is synthesized from absorbed acetate, producing palmitic acid (16:0) and stearic acid (18:0).

Broiler Nutrient Requirements

• Broilers are young, rapidly growing birds raised for meat. • The broiler industry has become very sophisticated in all aspects, with the result that poultry meat, is the least expensive meat available in the United States. • This is one of the reasons that per capita consumption of chicken has been steadily increasing. • Genetic programs have produced broilers with a very rapid growth rate. • These birds require nutrient-rich diets to meet genetic potential for rapid growth. • Broilers now reach market weight at less than 7 weeks of age • Broilers are fed multiple-stage diets, meaning that the composition is changed as age increases. • The starter diet is fed for the first 3 weeks and contains 23 to 24 percent crude protein. • A grower diet is fed from 3 to 6 weeks, • a finisher diet past 6 weeks. • Alternatively, a two-stage system with a starter and finisher diet may be used. • Feed is provided ad libitum to ensure maximum growth rate. • Broiler diets generally contain a coccidiostat to control coccidiosis. • Diets are usually fed as mash, although crumbles (rolled pellets) are sometimes used.

Brown Adipose tissue

• Brown adipose tissue (brown fat) is a special type of body fat especially important in newborn animals and animals that hibernate. • Brown fat is characterized by a well-developed blood supply, an abundance of mitochondria and respiratory chain enzymes, and a low activity of ATP synthase. • It is brown in colour because of the large numbers of mitochondria

Cellular Metabolism of CHO

• Carbohydrate metabolism is a fundamental biochemical process that ensures a constant supply of energy to living cells. • The most important carbohydrate is glucose, which can be broken down via glycolysis, enter into the Kreb's cycle and oxidative phosphorylation to generate ATP • Cellular metabolism is based on the catabolism of glucose, which involves the sequential degradation of the molecule through a series of enzymatic reactions. • The end result is the conversion of glucose to carbon dioxide and water, with the release of energy as ATP and heat. • The total energy released is equivalent to the solar energy required to synthesize glucose from carbon dioxide and water via photosynthesis. • There are two major pathways of glucose catabolism: - (i) glycolysis; - (ii) the citric acid cycle (Krebs cycle, tricarboxylic acid cycle or TCA cycle). • Hydrogen plays a prominent role in energy metabolism. • In photosynthesis, solar energy splits water into hydrogen and oxygen. • The light energy is transferred to hydrogen, which then binds with carbon to produce hydrocarbons (e.g. carbohydrates). • During the catabolism of glucose by animals, hydrogen is transferred from glucose to hydrogen receptors, such as NAD+ , NADP+ and FMN • The catabolism of glucose to carbon dioxide and water occurs in a series of steps, known as the two metabolic pathways of glycolysis and the citric acid cycle. • Glycolysis enzymes are located in the cytosol of the cell. • Glycolysis can function either aerobically or anaerobically. • The glycolysis pathway involves the breakdown of glucose (six carbons) to two molecules of a three-carbon end product (pyruvic acid in aerobic metabolism, lactic acid in anaerobic metabolism). • In this process, ATP is generated • Three B vitamins, thiamin, niacin and pantothenic acid, are involved in this step. • Niacin (B3) functions as a component of NAD. • Thiamin (vitamin B1) is a coenzyme for decarboxylation reactions, while pantothenic acid (B5) is a component of CoA. • In thiamin deficiency, glucose metabolism is impaired at this step, and pyruvate accumulates. • Deficiencies of these vitamins result in impaired energy metabolism, and deficiency symptoms which may reflect this impairment. • For instance, thiamin deficiency blocks energy metabolism at the decarboxylation reactions involved in formation of acetyl CoA and succinyl CoA, causing symptoms of energy deficiency, including polyneuritis (ataxia, opisthotonus or star gazing, convulsions), anorexia and hypothermia (lowered body temperature) • A significant cause of thiamin deficiency is the presence of dietary factors which destroy or inactivate the vitamin. • Thiaminases are enzymes which split thiamin into its two constituent rings, inactivating it. • Another pathway of carbohydrate metabolism is the pentose phosphate pathway (hexose monophosphate shunt, pentose shunt). • It does not generate ATP, but has two major functions: - the formation of NADPH, - the synthesis of ribose for nucleic acid formation.

Energy Requirements of Cats and Dogs

• Carbohydrates, fats, and proteins supply the energy necessary for support of metabolism of dogs and cats during maintenance, growth, reproduction, lactation, and physical activity (NRC, 2003). • Gross energy values are 4.1, 9.4, and 5.7 kcal/g for carbohydrates, fats, and proteins, respectively, in pet foods. • Metabolizable energy accounts for the energy lost in feces, in urine, and in fermentation gases. • As regards energy requirements of companion animals, the basal metabolic rate (BMR) is the energy required to maintain homeostasis in an animal in a post-absorptive state, lying down but awake, in a thermoneutral environment to which it has been acclimated. • Values for dogs range from 48 to 114 kcal/kg body weight ^0.75 . • The BMR of domestic cats and its relationship to body weight or surface area is currently unknown (NRC, 2003). • Maintenance energy requirements: - dogs range from 94 to 250 kcal ME/kg body weight0.75 . - cats, values range from 22 to 100 kcal/kg body weight0.75 . • As regards the basis for establishing energy requirements, allometric considerations of metabolic body weight are of great importance in dogs because of the wide range of body weights that exist among breeds (NRC, 2003). • Mature body weights of domestic cats range only from about 2 to 7 kg. The mass exponent often used for cats is 1, given that weights of various breeds of cats do not vary markedly (NRC, 2003). In terms of physiological state of the dog, growing puppies require nearly two times more energy per unit body weight than adult dogs of the same breed. • For adult dogs at maintenance, 132 kcal/kg body weight0.75 is valid for active young animals kept in kennels (NRC, 2003). • In terms of physiological state of the cat, newborn kittens have an energy requirement of about 20-25 kcal/100 g body weight. For adult cats at maintenance, 31-100 kcal/kg body weight are needed.

Chromium Importance

• Chromium is known to enhance the action of insulin , a hormone critical to the metabolism and storage of carbohydrate, fat, and protein in the body

Dinosaur Digestion?

• Clauss et al. (2003b) discussed fossil evidence of digestive type of extremely large mammals. • The fossil record, suggests that all extinct giant mammals (e.g. mammoths, mastadons, giant rhinos, giant ground sloths) were hindgut fermenters. • The same is likely true of dinosaurs (Farlow, 1987)

Categorizing Pet Foods

• Commercial pet foods also may be categorized according to the processing method used to prepare the food, the methods used to preserve the food, and the moisture content of the resulting foods. • Dry foods: - Contain between 6% and 10% moisture and include kibbles, biscuits, meals, and expanded products. - Cereal grains, meat, poultry, or fish meals, some milk products, and vitamin and mineral supplements are used in their preparation. For proper preparation of expanded products, the presence of starch is a requirement. - Kibbles and biscuits are baked products, whereas meals are prepared by mixing dried, flaked, or granular ingredients. • Expanded pet foods: - Are produced by the extrusion process, and this has essentially replaced use of kibbles and meals. - Extrusion involves mixing all ingredients together to form a dough that is cooked under conditions of high pressure and increasing temperature. - The dough moves through the extrusion machine. - The cooking process generally takes less than 60 seconds and allows for the complete gelatinization of starch with subsequent increases in diet palatability and digestibility. - At the end of the extruder, dies are used, resulting in selected shapes and sizes of the food. More fat and digest (palatability enhancer) are added to the outside of the expanded food after it is cooled. Moisture content of the final product is reduced to 10% or less by hot air drying. Expanded foods are the most common types of dry pet food produced and sold in the United States. • Canned pet foods: - May supply complete and balanced nutrition or may be a dietary supplement or treat containing canned meats or meat by-products. - Meat and fat ingredients are blended with water, after which dry ingredients are added and the mixture heated. Cans are filled on a conveyor line, then sealed and pressure sterilized, a process called retorting (250 C; 60 minutes). - Canned foods often are more palatable and digestible than dry pet foods and contain a higher proportion of protein (28-50%, dry-matter basis) and fat (20- 32%, dry-matter basis).Their water content is extremely high, approximately 75 percent. - Canned foods have a long shelf life. • Semi-moist pet foods: • Contain fresh or frozen animal tissues, cereal grains, fats, and simple sugars and have a moisture content ranging from 15 to 30%. • They are softer in texture than dry foods and are highly palatable, largely as a result of the presence of simple sugars. They contain 20 to 28% crude protein, and 8-14% of fat.

Other Minerals for Cats and Dogs

• Companion animals have requirements for other minerals in addition to calcium, phosphorus, magnesium, and zinc. • Macro-minerals required by dogs and cats in addition to calcium, phosphorus, and magnesium include sodium, potassium, and chloride. • Trace minerals required in addition to zinc include iron, copper, manganese, iodine, and selenium. • Briefly, both dogs and cats have a similar digestive tract except for its length (NRC, 2003). • Dogs with a body length of 0.75 m have an intestinal length averaging 4.5 m (small intestine, 3.9 m; large intestine, 0.6m). • Cats with a body length of 0.5 m have an intestinal length of approximately 2.1 m (small intestine, 1.7 m; large intestine, 0.4m). • Intestinal length is one factor that influences the amount of time that food resides in the gut which, in turn, influences the duration of digestion • A major difference in the gastrointestinal tracts of dogs and cats is the fact that the dog proximal stomach has a thinner mucous membrane with distinct gastric glands and the distal stomach has a thicker mucous membrane with less distinct glands (NRC, 2003). • An important function of saliva in the dog is evaporative cooling. Upon intense parasympathetic stimulation, the parotid gland of the dog secretes saliva at 10 times the rate of the human per gram of gland weight.

Salivation, eructation and rumination

• Compared with non-ruminants, ruminant animals secrete copious quantities of saliva. • The saliva is rich in sodium, potassium, phosphate and bicarbonate ions, serving to buffer the rumen VFAs. • It is also high in mucin content, serving as an antifoaming agent in the rumen to aid in prevention of bloat. • Urea is a component of ruminant saliva, functioning in urea recycling. • Salivary flow is influenced by the amount of time spent eating and ruminating

Mineral Requirements of Horses

• Considerable research on calcium and phosphorus requirements of horses has been conducted because of the importance of these nutrients in bone growth and skeletal development. • Deficient or imbalanced intake of these minerals results in inadequate mineralization of the bone matrix, causing lameness, crooked bones, and enlarged joints. • Excess phosphorus relative to calcium may cause nutritional secondary hyper-parathyroidism (big head). • Calcium insufficiency may also be induced by the presence of dietary oxalates, which impair calcium absorption, leading to signs of hyper-parathyroidism. Oxalates in tropical grasses are a common cause of this condition. • Sodium chloride (salt) is deficient in most of the feedstuffs offered to horses. • If, however, horses have continual access to loose salt or a salt block, they will usually consume adequate amounts to meet requirements. • Most commercial feeds do not contain adequate salt, so a supplemental source should always be available. • Care should be taken when providing salt to a horse of unknown salt status because overconsumption may cause excessive water intake, which can then lead to colic. • Trace minerals can be supplied by careful supplementation with commercial products. • There are elevated requirements for copper and zinc in broodmares and growing horses. • In some areas, selenium deficiency is a problem. In areas known to have selenium-deficient soils, a mineral mix with selenium should be used. • In areas with high levels of soil selenium, toxicity may occur. Signs of selenium toxicity in horses include loss of hair from the mane and tail, and hoof deformities, including excessive hoof growth and pronounced growth rings.

Carbohydrates Requirements For Dogs and Cats

• Dietary carbohydrates are a heterogeneous group of compounds ranging from simple sugars to complex polysaccharides. • Chemically, carbohydrates may be categorized as monosaccharides, disaccharides, oligosaccharides, and polysaccharides. • Carbohydrates sometimes fall into two or more different categories depending on: - animal species and age, - food-processing characteristics, - amount of food ingested. • Carbohydrates are not specifically required by dogs and cats, but they play key roles as sources of energy and as functional food components of the diet. • Absorbable Carbohydrates: Glucose and fructose are the main monosaccharides in dog and cat foods and are found primarily in cereal grains and by-products. • They are absorbed directly and do not require digestive enzymes to be absorbed. • In both dogs and cats, absorption of glucose and galactose across the brush border membrane occurs by an active sodium-dependent transport mechanism as well as sodium-independent simple diffusion. • Glucose and galactose are completely absorbed. • Glucose provides energy and supplies carbon skeletons, for biosynthesis of other compounds in the dog. • In the absence of dietary glucose, dogs synthesize glucose from amino acids and glycerol via gluco-neogenic processes. • Cats are in a constant state of gluco-neogenesis, implying that glucose is important for their normal metabolism. • Cats are somewhat unique in the manner that they handle glucose. • Cats have lower rates of glucose utilization as they have lower glucokinase activity, a hepatic enzyme that in other species is adaptive to diet and blood glucose concentrations. • So, even though cats may absorb dietary carbohydrates well, the rate of utilization of the resulting glucose likely is much less efficient.

Lipid Needs of Fish

• Dietary fats are a major energy source for most fish. • Fat metabolism in fish shows considerable differences from that of land animals. • The carcass fat has a high content of polyunsaturated fatty, making fish oils highly unsaturated. • In land animals, the carcass fatty acids belong to the oleic (omega-9) and linoleic (omega-6) series. • Marine fish have higher omega-3 (n-3) fatty acid levels than freshwater species. The dietary origin of these fatty acids is the phytoplankton at the bottom of the food chain.

What is Dietetics ???

• Dietetics refers to the formulations and preparation of diets to meet the needs of humans. • The comparable activity with domestic animals is the diet formulation

Avian Diets

• Diets for commercial production of poultry in the industrialized countries have become very sophisticated, with precise formulation to meet a lengthy list of required nutrients. • High-energy diets are used to maximize feed-conversion efficiency. • On large enterprises, use of low-energy diets could result in the need to handle much larger quantities of feed and increased labor, transportation, handling, storage, and feed hopper requirements. • The major types of commercial poultry raised in North America are chickens (layers and broilers) and turkeys. • Other poultry, of much less economic importance, include waterfowl (ducks and geese), guinea fowl, ostrich, and game birds, such as pheasants and quail. • These minor species in North America are more significant in other parts of the world. • Ducks are particularly important in Southeast Asia (e.g., Indonesia) and China, and geese are raised in large numbers in France and Eastern European countries (e.g., Poland, Hungary). • Guinea fowl (keets) are raised as meat birds in France, as are pigeons (squab). • Ostrich are raised commercially in South Africa for their feathers; they are becoming more common in the United States as meat producers, pets, and novelties. • Caged birds (finches, canaries, parrots, and so on) are raised as pets; some feed companies produce special diets for these species.

DIETS FOR RABBITS

• Diets for rabbits are based upon low-energy, high-fiber ingredients such as alfalfa meal and wheat milling by-products. • Inclusion of grains increases the incidence of enteritis losses and often reduces animal performance. • The digestive tract of rabbits is poorly adapted to the use of high-energy diets.

Autoenzymatic Intestines

• Digestion in the intestine begins in the intestinal lumen with the action of pancreatic enzymes, which break large molecules (proteins, polysaccharides) into smaller molecules (polypeptides, oligosaccharides). • These smaller molecules become trapped in the glycocalyx, which contains the enzymes that complete the digestive process. • Peristalsis is the process of muscular contractions by which the contents are moved along the intestine by a moving ring of contraction, pushing material ahead of it. Digestive and absorptive functions of the intestine are facilitated by a large surface area. To fit into the small volume of the body cavity, the small intestine is highly coiled In larger mammals, the first order of surface area enhancement is the presence of circular folds in the duodenum, increasing the surface area by a factor of about three. In all animals the main increase in surface area is achieved by small projections called villi, lining the intestinal mucosa and giving it a velvety appearance. The villi are very dynamic structures. Each villus is lined with a single layer of cells called enterocytes which are continually formed in generative areas called the crypts of Lieberkuhn, at the base of the villus The absorptive surface area of the small intestine is actually about 250 square meters (almost 2,700 square feet) - the size of a tennis court! • The surface area of the villi is greatly enhanced by minute projections called microvilli. • The microvilli in turn have filamentous fuzzy projections called the glycocalyx. • These filamentous appendages, rich in carbohydrate (as a component of glycoproteins), function in trapping nutrients for completion of digestion. Absorption of nutrients takes place across the surface of the villi, with the nutrients entering the circulatory system, or lymph in the case of lipids. Besides the enterocytes, the villi have goblet cells which produce and secrete mucus. Mucus protects the intestinal lining and provides lubrication to facilitate movement of digesta through the gut • In typical auto-enzymatic digesters, the bulk of digestion and absorption takes place in the small intestine, with the jejunum the principal area of absorption. • Digesta pass from the ileum into the hindgut, consisting of the caecum and colon (large intestine).

Vitamin A for Cats and Dogs

• Dogs differ from other domestic animals in their metabolism of vitamin A. • Dogs and some other members of the Carnivora order have unusually high concentrations of plasma vitamin A, mainly as retinyl esters (retinyl stearate and palmitate), and excrete retinol and retinyl palmitate in the urine. • Vitamin A toxicity is rare because, with the exception of the cat, animals are capable of regulating absorption of dietary B-carotene. • Preformed vitamin A absorption is not regulated in the intestine, so the cat can develop signs of toxicity. • Vitamin A deficiency is rare in dogs and cats because commercial pet foods contain adequate amounts of the vitamin. • Adult animals that are deficient in vitamin A will have poor reproduction, vision, and epithelial cell function.

Dry-Matter Intake (DMI) of Dairy Cows

• Dry Matter intake in dairy cow is one of the most important factors in nutrition. • The DMI of a cow or group of cows determines the concentrations of nutrients that must be in their ration to meet their needs. • Field nutritionists commonly use a factor of 2 lb of milk for each 1 lb of DMI as a benchmark to evaluate the farm's nutrition program.

NUTRIENT REQUIREMENTS OF WATERFOWL, RATITES,AND GAMEBIRDS

• Ducks are raised commercially in the United States to produce ducklings for the restaurant trade. • The White Pekin breed is the principal meat producer. • In China and Southeast Asian countries, such as Indonesia and Thailand, ducks are raised extensively for meat and eggs. • Egg-producing breeds, such as the Indian Runner, can achieve eggproduction rates equal to or greater than those of chickens. • In Asia, duck raising is often integrated into crop production by herding the ducks through rice fields to control insects and to harvest waste grain. • Geese are the other major waterfowl raised commercially. • Goose production is a minor activity in North America, but large numbers are raised in European countries such as France, Hungary, Poland, and Russia. • They are raised to produce meat, feathers, and in France, liver pate (pate de foie gras). • Fatty livers are produced by force-feeding the birds with a high-energy diet. • Other birds raised commercially for meat production, especially in Europe, are: • pigeons and guinea fowl. • The young birds, known as squabs (pigeons) and keets (guinea fowl) are considered delicacies. • Diets adequate for chickens can be used for these birds. • Ostriches and other ratite birds (emu, kiwi, cassowary, rhea) are large, flightless birds that have been separated from the main lines of avian evolution for 80 to 90 million years, since the Middle Cretaceous period. • Their occurrence in Africa, South America, and Australia stems from having common ancestors that lived when these continents were joined. • These birds have enlarged ceca with microbial fermentation and utilize fibrous vegetation to a considerable extent. • There is evidence of nitrogen recycling from the cloaca to the cecum, increasing the efficiency of protein utilization. • The metabolic rate is lower than for other avian species, thus contributing to their ability to survive on low-quality diets. • To a limited numbers of ratites such as ostriches and emus are produced commercially in North America. • The ME values of alfalfa and high-fiber grains, such as oats and barley, are higher for ostriches than for chickens because of fiber fermentation in the ceca.

Ketosis in sheep

• During the last trimester of pregnancy, ewes are quite susceptible to ketosis which may result in pregnancy disease, pregnancy paralysis, or twin-lamb disease. • Ketosis is caused by a metabolic shortage of glucose and excessive reliance on mobilized body fat to meet energy requirements. • Mobilization of body fat produces ketogenic acetate, rather than allowing for glucose biosynthesis. • Symptoms of ketosis, such as coma, are due to inadequate blood glucose to support brain metabolism, while excess acetate from fat metabolism is converted to ketones (e.g., acetone). • There is some indication that mild feed restriction in mid-pregnancy, might be desirable because overfat ewes are susceptible to feed intake reduction in late pregnancy, making them more likely to experience ketosis

Energy Storage

• Energy is stored mainly as triacylglycerol (TAG, in adipose tissue) or carbohydrate (glycogen). • More energy is stored in a given weight of tissue as TAG than as carbohydrate. • TAGs are energy-rich (9 kcal/g) as compared to carbohydrate (4 kcal/g), so per unit of body weight, more energy can be stored as TAG. • Saturated fatty acids yield more energy than unsaturated fatty acids, because they contain more hydrogen (ATP is formed when hydrogen-containing cofactors, e.g. FADH2 , NADH, NADPH, are oxidized in the respiratory chain)

Rabbit Energy Requirements

• Energy levels in typical rabbit diets are quite low, usually being in the range of 2,400 to 2,800 kcal DE/kg diet. • Higher energy diets tend to promote microbial overgrowth in the cecum and lead to enteric disease (diarrhea). • Therefore rabbit diets usually contain alfalfa meal or other fibrous feedstuffs as the main ingredient. • Rabbits do not digest fiber efficiently. • Their digestive strategy is to eliminate fiber rapidly and retain the non-fiber components in the cecum for fermentation, followed by cecotrophy.

Energy Requirements for Avian

• Energy requirements of poultry are usually expressed in terms of ME. • High-energy cereal grains are the principal energy sources used in modern poultry diets. • Fat is often added at levels of 3 to 8 percent to increase the dietary energy concentration.

GENERAL NUTRITIONAL PROBLEMS OF RABBITS

• Enteritis - One of the major problems in commercial rabbit production is enteritis. - Most cases of enteritis are enterotoxemia, meaning that such cases are caused by bacterial toxins elaborated in the gut. - The major organisms involved are Clostridium spiroforme and toxigenic strains of E. coli. • Enterotoxemia (Entero-toxemia) Of particular importance in weanling rabbits. - At weaning, the gut of the young rabbit is susceptible to microbial invasion because the stomach pH (approximately 5) has not dropped to the very acid (pH 1.5 to 2) to bactericidal level typical of the adult rabbit. - If the diet is high in energy (from starch or other readily fermentable carbohydrate), carbohydrate overload of the hindgut may occur, with a proliferation of microbes in the cecum. - The high quantity of VFA causes a temporary drop in cecal pH, killing many of the normal microbes and allowing proliferation of pathogens such as C. spiroforme and E. coli, which produce lethal toxins.

Energy Requirements of Beef Cattle

• Expressing energy requirements and energy values of feedstuff's for ruminants is somewhat more complex than for swine and poultry because of rumen fermentation and the complexity of interactions between diet and fermentation end products. • One example of this complexity is the effect of balance of absorbed VFA on metabolic efficiency. • If there is a surplus of acetate (C2 ) or a deficiency of propionate (C3 ), the C2 energy cannot be utilized in the citric acid cycle reactions of metabolism. • There is an extra loss of heat energy associated with conversion of amino acids, to citric acid cycle intermediates. • This extra loss of heat energy, reduces the net energy value of the diet. • For ruminants, DE is less suitable as a measure of feed energy than for swine because of the variable losses of rumen gas energy (mainly methane). • The major weakness of DE, as a basis for feeding systems for ruminants, is that it overestimates the available energy of high-fiber feedstuff's relative to concentrates • Energy requirements are modified by environmental conditions. • Beef cattle are particularly likely to be exposed to extremes in environment as opposed to confinement-housed animals, such as swine and poultry. • These conditions include very hot or cold weather, wind velocity (wind chill factor), precipitation, and animal factors such as age, breed, hair coat, body condition, period of adaptation, and diet. • Environmental temperature affects net energy values. • In the thermal neutral or comfort zone, or above the comfort zone, the heat of rumen fermentation is detrimental, representing excess heat that must be eliminated. • Under cold conditions, the heat of rumen fermentation and the heat of nutrient metabolism (the heat increment) are beneficial in helping to maintain body temperature and, therefore, contribute to the NE of a feed. • Low-quality forages have a high heat of rumen fermentation, so straw and other coarse feeds are of greater value in cold environments than under moderate conditions. • Animals adapted to cold make the adaptation through changes in hormone secretion; in cold-adapted animals the comfort zone can be shifted significantly to lower temperatures. • Energy intake of beef cows is a major determinant of reproductive efficiency. • It is of particular concern in relation to estrous cycles and initiation of pregnancy. • After calving, beef cows should be rebred within 60 to 90 days to maintain a once-peryear calving interval. • This postpartum period is one of high energy requirements to support lactation. • If a cow is not able to consume sufficient feed to maintain a positive energy balance, initiation of estrous cycling may not occur, resulting in a prolonged calving interval.

Fats Requirements for Dogs and Cats

• Fat serves several functions in a companion animal diet. • First, dietary fat provides energy to the animal. • Compared with carbohydrates and protein, fat provides the highest amount of metabolizable energy (2.25 times more than either protein or carbohydrate). • In addition to having high ME, fat in pet foods is very digestible. • The apparent fat digestibility of commercially available diets ranges from 70% to 90% percent for dog food and 85% to 94% percent for cat food. • Other functions of dietary fat are to act as a carrier of fat-soluble vitamins and provide essential fatty acids (EFA) to the animal. • Essential fatty acids are required for normal growth and metabolism and cannot be synthesized in adequate amounts by the animal. • All EFAs are polyunsaturated fatty acid. The body has a requirement for two families of EFAs: the n-6 and n-3 series. • The NRC (2003) recommends that linoleic acid be provided at 9.5 g/kg dry matter (DM) for adult dogs at maintenance. • The cat is unable to synthesize adequate amounts of arachidonic acid from linoleic acid because the cat has low delta-6-desaturase and delta5-desaturase activities. • Because of the low enzyme activities, the cat diet must contain both linoleic and arachidonic acid. • The NRC (2003) recommends that a cat at maintenance be supplemented with 0.02 g arachidonic acid/kg DM and 5.5 g linoleic acid /kg DM. • A third function of dietary fat is to improve palatability, of flavor, of the diet. • Fat also improves the texture of the diet. • Dogs can adapt to a wide range of fat concentrations in the diet, but studies have shown that they prefer animal fats. • Generally, cats prefer a high-fat diet to a low-fat diet, and they appear to prefer fats of animal origin as well

Estimation of Feed Energy

• Feed energy is actually measured as calories, by bomb calorimetry, and then converted to joules by a conversion factor (below). Appropriate definitions and conversions are as follows: • 1 calorie (small calorie) = the amount of heat required to raise the temperature of 1 g of water by 1°C degree centigrade, measured from 14.5 to 15.5°C; • 1 kilocalorie (kcal) = 1000 calories = 1 Calorie (large calorie);1 • 1 megacalorie (Mcal) = 1000 kilocalories; • 1 calorie = 4.184 joules (J);

Feeding Behavior

• Feeding behavior and digestive tract physiology in animals are closely interrelated. • The feeds normally consumed by animals are those they are capable of digesting. • There are three major types of animal feeding behavior: • (i) carnivorous; • (ii) omnivorous; • (iii) herbivorous.

Energy Needs of Fish

• Fish have lower maintenance energy requirements than mammals and birds because they do not have to maintain a constant body temperature, they exert less energy in movement in water than birds and mammals do on land and air, and they excrete ammonia rather than urea or uric acid and thus do not have the energy costs of synthesizing these compounds.

Mineral Needs of Fish

• Fish require the same mineral elements as other animals but can often obtain adequate quantities of many minerals from the water. • Excretion and absorption of minerals across the gill membranes serve an osmoregulatory function as well as a nutritional role. • Calcium requirements are usually met by absorption from water, whereas phosphorus is a dietary requirement. • Fish require a dietary source of selenium; organic selenium compounds such as seleno-methionine and selenium in yeast have higher selenium bioavailability than sodium selenite.

Vitamin Needs of Fish

• Fish require the same vitamins as land animals; in addition, many fish require vitamin C (ascorbic acid). • Ascorbic acid has a metabolic role in the synthesis of connective tissue; it functions in forming cross-links between collagen fibers. Deficiency signs are related to the role of vitamin C in collagen formation and include scoliosis (lateral curvature of spine) and lordosis (vertical curvature). • Some species, such as salmon, synthesize ascorbate-2 sulfate, which is a tissue storage form of the vitamin. • The precision with which some of the vitamin requirements are known is not very high. • Carotenoids are needed for pigmentation of the skin and flesh of colored fish, such as the rainbow trout. • Carotenoids, xanthophylls, and similar substances used in the poultry industry can be used as pigmenting agents for fish. • Astaxanthin is absorbed and retained in the flesh more efficiently than canthaxanthin; a combination of the two pigments maximizes flesh pigmentation. • Shrimp, daphnia, crabs, and some other herbivorous aquatic animals accumulate phytoplankton carotenoids, mainly astaxanthin, and are good pigmentors when used as feed for salmon and trout.

Carbohydrate Needs of Fish

• Fish seem to use most carbohydrate sources poorly. • Starch in grains has a digestibility of only 20 to 40%. • Cooking or heat treatment (e.g., extrusion) improves starch digestion considerably. A problem with carbohydrate utilization is that fish may store excess quantities of glycogen in the liver. When liver glycogen levels exceed 16%, death may occur, apparently due to kidney malfunction and nephrosis. • In contrast to most animals, fish do not mobilize liver and muscle glycogen during fasting. • During starvation, fish mobilize lipid first, then protein, and carbohydrate only during the final stages. Fish may survive a considerable period of time (even years, in some cases) after reaching the "point of no return" from fasting, after which irreversible metabolic changes occur that lead to death.

Mineral requirements for Swine

• For macro-minerals, practical grain-oilseed meal diets are deficient in calcium (Ca), phosphorus (P), sodium (Na), and chloride (Cl). • Calcium and P are essential for normal skeletal growth, bone mineralization, and bone strength. • All plant feedstuffs used in swine diets are low in Ca and P. • The bioavailability of P in plant sources is very low because of the presence of phytate. • Common dietary sources of P, which also provide Ca, include dicalcium phosphate, bone meal, and defluorinated rock phosphate. • Ground limestone is an economical source of Ca, and it does not contain P. • The requirements for salt (NaCl) range from 0.40 percent of the diet for sows and weaning pigs to 0.20 percent for finishing pigs. • However, NaCl supplementation usually ranges from 0.25 to 0.50 percent in practice. • Even though animal plasma and dried whey contribute Na and Cl to the weaning diet, pig performance is improved when salt is added to increase dietary Cl to 0.38 percent • Micro or trace minerals are provided using a trace mineral premix that is added to the diet at a small, specified percentage ranging from 0.10 to about 0.30 percent. • This premix should contain high - quality salts (sulfates, carbonates, chlorides, etc.) of zinc, iron, copper, and manganese, plus appropriate forms of iodine and selenium. • Deficiencies of these nutrients lead to smaller litter size and greater baby pig mortality. • The iron requirement of the baby pig is also increased because of its: - rapid growth rate, - high rate of hemoglobin synthesis, - low placental transfer or iron, - low transfer of iron into sow milk. Attempts to improve the iron status of baby pigs by supplementation of gestation and lactation diets with iron have been unsuccessful.

TYPES OF PET FOODS

• From a marketing perspective, commercial pet foods may be categorized into generic, private label, popular, and premium brands. • Generic foods carry no brand name and usually are marketed within a rather narrow region of the country. • They generally are the lowest cost of any commercial food. Inexpensive ingredients are used in their preparation and little, if any, animal testing is conducted to determine their nutritional efficacy. They may suffer from low palatability by the animal along with low nutrient digestibility and bioavailability. • Private label pet foods carry the name of the store where they are sold, even though they often are produced by the same organization that prepares generic foods and often are of the same general nutritional quality. In many cases, they are generic foods packaged and labeled with the name of the selling entity • Popular brand pet foods are sold nationally and (or) regionally in grocery store chains. • Their name recognition is high as a result of effective advertising. • Nutritionally, these foods are often highly palatable to the animal but vary widely in ingredient content among batches depending on ingredient price at the time of manufacture. • Nevertheless, the ingredients used are of higher quality than those present in the former two categories, resulting in higher nutrient digestibility and bioavailability • Premium brand pet foods contain high-quality fixed ingredients that result in excellent palatability and high nutrient digestibility and bioavailability to the animal. • These foods are targeted to pets at different life stages and (or) those following different lifestyles. Previously, these foods had limited distribution in pet supply stores and in the offices of the veterinarian, but now are widely available in the supermarket as well. • Premium foods are of particular use to pets housed indoors and to pets who have the opportunity to excrete feces and urine only twice daily. • Besides the brands previously listed, there also exist homemade diets and veterinary diets. One popular homemade diet, Bones And Raw Food (BARF), consists of a raw meat-based diet.

Other Nutritional Problems of Rabbits

• Fur chewing is a common problem in rabbits; - animals pull and consume their own hair or that of other animals in the cage. - Besides ruining the pelt of market animals, fur chewing leads to hairballs in the stomach. Animals with hairballs stop eating and eventually die of inanition. - Fur chewing seems to occur mainly when the diet is inadequate in indigestible fiber. Reproduction in rabbits is influenced by nutrition. Inadequate energy intake may result in resorption of the fetuses, or small, weak litters at birth. Excessively fat does will similarly have small, weak litters and poor milking ability. One of the major causes of poor reproduction during the winter is inadequate energy intake, often a result of limit-feeding the same amount of feed, as provided in the summer.

GI Hormones

• GRP = Gastrin Release Peptide, • VIP= Vasoactive Intestinal Peptide, • GIP= Gastrin Inhibitory polypeptide, • Substance P= undecapeptide, neuropeptide family. Acting as a neurotransmitter and as a neuromodulator.

Storage of Glycogen

• Glycogen is the major storage carbohydrate in animals. • It is sometimes called animal starch, and like plant starch, it is a branched polymer of a-D- glucose. • Glycogen is stored in the liver and muscle tissue. • The main function of liver glycogen is to provide glucose to maintain the blood glucose concentration (glucose homeostasis), to provide a constant supply of glucose for extrahepatic cellular metabolism. • Muscle glycogen is a readily available source of fuel for muscle contraction. • Glycogenolysis is the process of glycogen breakdown. • In liver, this process yields glucose, while in muscle the major end product is lactic acid.

FEEDING AND NUTRITION OF GOATS

• Goats are raised to only a limited extent in North America. • They have a low status, often being considered a "poor man's cow." • Modest numbers of dairy goats are raised in the United States, and a considerable number of Angora goats are produced in Texas for mohair • Meat-producing goats are raised in the southwest United States; the meat is consumed primarily by Spanish-speaking Americans. • Since this population is increasing, the demand for goat meat has also increased in the past decade. • Some meat-producing (Spanish) and Angora goats are used in brush control programs in California to control chaparral, a fire- susceptible shrub ecotype. • With increasing restrictions on the use of herbicides, employment of goats for brush control may increase. • Goats are intermediate feeders with a propensity to browsing. • They are quite fastidious in their eating behavior and select succulent and nutritious vegetation. • In comparison to cattle and sheep, goats derive a much larger portion of their feed from browse if given the opportunity. • Goats prefer grasses over legume forages such as clover and alfalfa. • They have the ability to stand on their hind legs to browse (bipedal stance) and are very nimble and can even climb some trees to reach the leafy vegetation. Goats are well adapted to arid climates, being heat tolerant and having low water requirements. They can go several days without drinking and are capable of traveling large distances for feed • The lignin content of browse increased above 12%, goats were superior to sheep in digestion and intake of highly lignified material. • They suggested three possible mechanisms: - differences in rumen environment, - rumen retention time, - chewing and rumination behavior. • On low N diets, goats maintain higher rumen ammonia concentrations, perhaps by greater nitrogen recycling. • Higher rumen ammonia would presumably result in greater microbial activity on low N diets. • Goats have a longer rumen retention time than sheep, possibly increasing digestibility due to a longer exposure of lignified material to microbial action. • Goats also have a longer rumination cycle than sheep, which could result in greater physical degradation of lignified browse and increased digestibility.

Hibernation

• Hibernation is a state of hypometabolism entered into by some animals as a response to anticipated nutritional stress. • While generally viewed, as a means of avoiding winter-feed scarcity and cold, hibernation is employed also by some animals (e.g. California ground squirrel) to avoid hot summer months when grass seeds are unavailable (also called aestivation) • Aestivation in hot, dry conditions is common among reptiles. • Hibernation is characterized by an extreme drop in body temperature (to as low as -2.9°C) and metabolic rate can be as low as 1% of normal. • This state is known as torpor. • A typical hibernation season is characterized by several bouts of torpor, interrupted by short periods of intense metabolic activity. • For reasons as yet unknown, they expend significant amounts of energy to periodically rewarm back to normal body temperature for less than a day before recooling. • Hibernators are of two types: • (i) fat storing; • (ii) food storing. • Fat-storing hibernators do not consume food during the hibernation season and instead rely on metabolism of stored fat (white adipose tissue; WAT). • Fat-storing hibernators, such as ground squirrels and marmots, can virtually double their body weight prior to hibernation, with 60-80% of the weight as WAT. • Adipose tissue is the most efficient form of fuel storage, because body fat is energy dense, and non-hydrated. Body protein is also catabolized for energy during hibernation. • Hibernating bears utilize protein for energy, and recycle urea back into amino acids, by ammonia fixation. • Food-storing hibernators (e.g. chipmunks) store caches of food, which they ingest during their periodic arousals.

Vitamin Requirements of Dairy Cows

• Historically, supplementation of water-soluble vitamins to ruminant animals has not been needed. • Advances and understanding of dairy nutrition have suggested that, under some conditions, supplemental B vitamins may provide some health and production benefits. • Positive responses to supplemental biotin, choline, and niacin have been reported in the literature. • Supplemental biotin (20 mg/head/day) improves hoof health and reduces lameness in both intensively-managed and in pasture fed dairy cattle • Supplementing B vitamins must be evaluated on a case-by-case basis, and no blanket recommendations can be made at this point. • When considering the use of B vitamins in diets fed to dairy cattle, the cost-tobenefit ratio should be examined and decisions based on benefits as compared to the cost of incorporation. • Unlike water-soluble vitamins, fat-soluble vitamins are usually supplemented to dairy cattle.

THE DIGESTIVE SYSTEM AND FEEDING MANAGEMENT of Horses

• Horses are non-ruminant herbivores and continuous grazers. • Management of many horses includes keeping them in stalls or dry-lots (small enclosures with little or no vegetation) and feeding them two or three times a day. • The digestive system of the horse evolved to digest low-nutrient forages in an animal that grazes for 16 to 18 hours per day. • When placed in management situations where they must conform to human schedules, horses are often fed higher-energy diets twice a day. • The result is reduced exercise and boredom along with digestive disturbances and the development of behavioral vices or abnormalities such as cribbing and wood chewing • Microbial activities of the hindgut of the horse are similar to ruminal fermentation. • The principal microorganisms populating the hindgut of horses are similar to those found in the rumen with some variation in relative percentages. • Bacteria, protozoa, and fungi constitute the majority of microbes • The microbes have the ability to break down the structural carbohydrates cellulose and hemicellulose through fermentation. The products of this fermentation process are volatile fatty acids and methane gas. • The volatile fatty acids acetate, propionate, and butyrate can provide a significant proportion of the energy needs of the horse. • The remaining energy needs must come from digestible nonstructural carbohydrates, protein, and fats in forages or grains. • Changing rapidly from a medium to low-quality hay diet to either a lush pasture or a high-grain diet will upset the microbial balance of the hindgut. • The most serious situation would be a horse that eats large amounts of grain accidently. • Fast-growing spring and in fall pastures or pastures containing more than 25% of clover can also cause soluble and highly fermentable carbohydrate overloads. • The overload of non-structural carbohydrates causes a proliferation of grampositive bacteria such as Streptococcus bovis and Lactobacillus spp., often causing laminitis. • These bacteria produce lactic acid, which can lower the pH of the hindgut. • Acid-sensitive gram-negative bacteria are killed at lower pH levels, releasing endotoxins from the cell walls and into the circulatory system. • The combination of lactic acid, decreasing pH, and endotoxins contributes to laminitis. • Horses suspected of grain overload need immediate veterinary attention. • The laminitis process can take from 18 to 28 hours before obvious signs of the condition are seen. • Once in the latter stages, there is little that can be done to stop the cascade of events that eventually leads to the separation of the sensitive and insensitive lamina of the hoof and rotation of the coffin bone • When adapting horses to pasture, grain, or hay, changes must be made slowly. • Horses should be allowed access to pasture for short periods of time while continuing to be fed hay when confined. • When changing the diet, intake of any feedstuff should not be altered by more than 25% by weight per day

Ancestral Human diet, Palaeolithic Nutrition (the Caveman diet)

• Human nutritional requirements reflect our evolutionary history extending millions of years into the past . • Genetically, today's humans are basically the same biological organisms as our ancestors when they took up agriculture a scant 3000-10,000 years ago. Thus our ancestral dietary pattern has continuing relevance to the nutritional needs of contemporary humans • Small populations of hunter-gatherers still exist. These populations have a low dietary intake of fats rich in saturated fatty acids, because of the leanness of wild game. • However, their cholesterol intake was high, about 480mg/day. Despite this, they maintain very low serum cholesterol concentrations (about 1,250 mg/L). • Their high ratio of polyunsaturated to saturated (P:S) intakes (1.4 for hunter-gatherers, 0.4 for contemporary Americans), low saturated fatty acid intake and low total fat intake apparently balance the high cholesterol intake. • Ancestral human diets contained much more protein and fiber than do contemporary diets. • Thus meat consumption is consistent with good health, which, based on archaeological evidence, hunter-gatherers apparently enjoyed. • However, the fatty acid composition of contemporary intensively fattened meat animals deviates markedly, in an undesirable manner, from the lipid content and fatty acid composition of wild game animals. • In a review of palaeolithic nutrition (the caveman diet) point out that, while early humans consumed a diet high in meat, the actual nutrients consumed may have been quite different from those in today's Western-type diet. • The importance of meat in the caveman diet is revealed by the abundance of animal bones and hunting tools in archaeological sites, and the absence of much evidence of plant foods and tools • While the human genetic profile has not changed much in the past 40,000 years, our current Western diet has changed markedly over this time, with an increase in total fat, saturated fatty acids, trans-fatty acids and ω-6 essential fatty acids, but a decrease in ω-3 fatty acids. • The ratio of ω-6 to ω-3, and fatty acids is 10-20:1 today, whereas in preagricultural times it was about 1:1. This change arose because of our use of vegetable oils (mainly ω-6) and grain-fed meat animals, with carcass fat high in saturated and ω-6 fatty acids. • The major dietary energy sources for modern humans are the cereal grains (cereal grains are the edible seeds of grasses). • Three cereal grains, wheat, maize (corn) and rice, make up over 75% of world grain production, providing over half of the food energy consumed by humans. • When cereal grains replaced the animal-based diets of hunter-gatherers, there were characteristic negative effects such as a reduction in stature, increased infant mortality, reduced lifespan, increase in infectious diseases, increase in iron deficiency anemia, increased osteomalacia, and increased dental caries and enamel defects.

Pet Food Market

• In 2002 , the global market for pet food and pet care products was valued at U.S. $46 billion, up 2.6% from the previous year. • This translates into nearly 17 million tons of food produced annually. • Sales in North America were responsible for 41 % of the global market value. • Western Europe accounted for a further 30.5 % of the global market, and Japan another 13 %. • Both Mexico and China are experiencing annual double -digit rates of growth in pet food sales. • The continued expansion of the industry worldwide is driven by increased pet populations, increased spending per pet, and an increased use of prepared pet foods and treats in both developed and emerging nations. • Product segmentation strategies also stimulate growth, with brands of food being offered for various life stages, lifestyles, and breeds of pets. • "Humanization" of pets has resulted in consumers purchasing foods paralleling human tastes (e.g., gourmet flavors of cat foods, treats for dogs and cats). • The popularity of the "pet superstore" has made pet accessories and, more importantly, premium and super-premium dry dog and cat foods (those high in animal protein ingredients and high in digestibility) very accessible to the consumer. • In spite of the relatively large numbers of companies that make pet food yet today, the global market for pet food and pet care products remains concentrated in the hands of two main manufacturers, Mars and Nestle. • Other companies like lams have benefitted tremendously from the growth surge in premium and super-premium foods, and their products are now available in the supermarket.

Osteomalacia

• In adults, bone demineralization occurs with a deficiency of calcium, phosphorus and/or vitamin D. This condition is known as osteomalacia (adult rickets).

Colonic and caeco-colonic fermenters

• In all large (over 50 kg) hindgut fermenters, the enlarged proximal colon is the primary site of fermentation. • Examples include: - Horse and other equids (zebra, donkey); - Elephant and rhinoceros. • The caecum is often enlarged as well, but performs as an extension of the colon as a fermentation site, rather than functioning in selective retention of small particles as in the caecal fermenters. • Caeco-colonic fermenters also include a number of New World monkeys, lemurs and rodents. • The digestive strategy of colon fermenters is similar to that of ruminants. • Some caeco-colonic fermenters engage in coprophagy, which is the consumption of feces. • Coprophagy is different than caecotrophy, which involves the consumption of caecal contents rather than feces • On low protein diets, horses will consume their feces, presumably as a means of conserving nitrogen. • Wild horses on North American often practice coprophagy, probably as a nitrogen conservation measure, when consuming mature weathered forage in the winter.

Autoenzymatic Hindgut

• In autoenzymatic digesters, the cecum is relatively small. • The main digestive functions of the hindgut are the absorption of water and electrolytes. • As a result, the feces are normally quite dry in comparison to the intestinal contents. • The hindgut is also an area of anaerobic microbial growth, which is of some nutritional importance in autoenzymatic digesters, and of much greater importance in animals with hindgut fermentation.

Volatile Fatty Acid (VFA) Metabolism in Ruminants

• In contrast to simple non-ruminants, ruminants absorb very little glucose. • Their major absorbed energy sources are the VFAs, the end products of microbial fermentation in the rumen. • Thus three B-complex vitamins (pantothenic acid, biotin, vitamin B12) are involved in propionate entry into the citric acid cycle. • Propionate metabolism is consequently impaired with vitamin B12 deficiency. • Vitamin B12 is a complex molecule containing chelated cobalt. • The only known metabolic function of cobalt is its role as a constituent of vitamin B12 • Ruminants have a relatively high cobalt requirement, and may develop wasting disease on pastures that support grazing horses with no sign of deficiency. • Two factors that contribute to the high cobalt requirement of ruminants are an inefficiency in ruminal vitamin B12 synthesis, and a low ability to absorb vitamin B12.

Natural Diets and Feeding Behavior

• In developing feeding programs when data is unavailable, it is useful to begin by considering the diet of the animal in the wild state. • Even obtaining this information may be difficult, and often only represents a single moment in time. • With game animals, digestive contents of freshly killed animals can be examined to identify feeds consumed. However, a list of species consumed provides only partial information necessary for applied feeding programs. • We can rarely duplicate the ingredients of any animal's diet in captivity— what we can duplicate are the nutrients consumed. • Some animals have evolved dependence on particular plants; these specialized feeders can be some of the most difficult to feed in captivity. • Some of the Australian marsupials will feed only on Eucalyptus spp. Koalas, for instance, will eat only foliage from certain eucalyptus trees, so their exhibition in zoos is feasible only in areas where the trees can be grown, or suitable browse must be purchased and brought into the facility. • The koala can absorb several ml of eucalyptus oil daily, a dose that is fatal to humans. • Another example, the giant panda, in the wild eats primarily bamboo, but it can be induced to eat other feed in captivity. • The panda is interesting in that it is an herbivorous carnivore! • It is a member of the order Carnivora and has a gastrointestinal tract physiology similar to that of other carnivorous species, with a simple stomach, no cecum, and a short colon. • It has adapted to a herbivorous diet by having a high feed intake and rapid time of passage, digesting the cell contents and excreting the cell wall material as indigestible residue. A number of reptiles are herbivorous. • On a more modern level, reptiles such as the desert tortoise have a large but simple gut with hindgut fermentation that allows the animal to survive on poor-quality, highly fibrous desert vegetation. • The giant land tortoises (Galapagos, Aldabra) are also well suited to grazing habits, with a horny beak for clipping forage, and an ileocolic valve to retain foodstuffs in the gut for 10 to 30 days. • Iguanas are highly herbivorous, employing gut valves as well as probable nematode symbionts to assist with digestion. • Green iguanas showed better growth with 19-24% versus 27% Non Digestive Fibers. • Native foods (flowers, fruits, leaves, and seeds) eaten by herbivorous lizards are moderate in protein and fiber content, averaging around 10% crude protein. • There are a number of aquatic herbivores such as the manatee (sea cow) and green sea turtle. • Both of these species have very high (80%) efficiencies of cellulose digestion associated with hindgut and even small intestinal fermentation. • In the case of marine mammals, there are no suitable domestic species from which to extrapolate dietary requirements.

Digestive Tract of Fish

• In terms of digestive tract physiology, fish are monogastric, although technically some species, such as carp, have no stomach and, therefore, might better be called agastric. • Channel catfish, salmonids, and most other fin fishes have true stomachs with hydrochloric acid and pepsinogen secretion. • Digestion is accomplished by digestive enzymes similar to those of other animals; the major sources of digestive enzymes are the stomach, intestinal mucosa, pancreas, and pyloric ceca • Digestion of algae cell walls is facilitated by a strongly acid stomach. • Some nutrients, such as calcium, are absorbed directly from the water via the gills. • Herbivorous fish, such as the grass carp, eat large amounts of vegetation. Although they have cellulolytic gut microbes, they derive nutrients mainly from the non-fiber fraction. • The intestinal tract in carnivorous fish is shorter than in herbivorous or omnivorous species, as is true with mammals. Compared to mammals, fish have a very short intestinal tract, which is not separated into a small and large intestine. • Volatile fatty acid production in herbivorous fish can be nutritionally significant.

Calcium importance and functions

• It is the main element in bone tissue, that include 99% of the corporal calcium, and around 75% of all phosphorus in the body (Bones and teeth). • Adult cow has: 6 kg of calcium, and 2.8 kg of phosphorus in the body, the correlation of Ca:P is 2:1. • In the milk that correlation is 1:1 (can cause deficiency of P) • In the sheep, that correlation Ca:P is 3:1 Calcium Functions: - Formation of bone matrix - Essential factor in the coagulation of the blood - Participation in the muscle contraction process - Act as adjuvant in the process of neural signaling transmission - Enzyme regulation (calmodulin, muscle contraction) - Act as a second message to some hormones

Layer Hen Nutrient Requirements

• Layers are chickens raised for egg production; most are of the Leghorn breed. • They are smaller bodied than the meat breeds and have a slower growth rate and, therefore, lower nutritional requirements than broilers during the early growth stages. • Because of the high nutrient content of eggs and the high level of production of modern layers, the nutritional requirements of birds in full production are very high, particularly for protein, energy, and calcium. • Flock replacement chicks are fed a 20% crude protein all-mash starter diet for the first 6 weeks. • Followed by a 15% to 16% protein grower feed to 12 weeks; • 12% to 13% protein developer feed until sexual maturity (age at first egg laying, approximately 18 to 20 weeks); • Feed may be restricted during the developer period to delay onset of sexual maturity.

Leg Disorders of Swine

• Leg disorders and lameness are common problems in pigs raised in confinement, particularly on concrete or slotted floors. • The balance of calcium, phosphorus, and vitamin D may be involved.

Magnesium For Cats and Dogs

• Magnesium plays a role in muscle and nervous tissue function and is an important cofactor in several enzymatic reactions. • Approximately 50% of the magnesium in the body is found in bone, while the majority of the remaining magnesium is found in the cytoplasm of soft tissues. • Magnesium toxicity is very rare in dogs and cats because excess concentrations are excreted in the urine instead of being absorbed. • Excess magnesium has been shown to increase the risk of urolithiasis and feline lower urinary tract disease (FLUTD).

Methane Production

• Methane production by ruminants is nutritionally significant. • Methane, also known as natural gas, represents a major loss of energy in rumen metabolism. • From 4 to 10% of the gross energy intake is lost to the animal as a result of rumen methane production. • Development of ways to reduce ruminal methane would increase the efficiency of ruminant production. • The amount of methane produced in ruminants is determined in large part by diet. • Intensive cattle production, using high concentrate diets and ionophore feed additives, can reduce the contribution of cattle to global warming by the following means: - Methane production per unit of feed is reduced on high concentrate diets. - Ionophores lower methane production in the rumen by altering rumen fermentation. - Ionophores decrease the amount of feed required to produce a given amount of weight gain, further reducing methane production. - Both high concentrate diets and ionophores (and other feed additives and implants) increase growth rate, reducing the age at slaughter. - Thus with a shorter lifespan, the animal has a lower lifetime methane production.

Minerals and Vitamins for Sheep

• Mineral and vitamin requirements and metabolism of sheep are, in general, similar to those of beef cattle. • Ewes are unable to absorb sufficient calcium in late pregnancy and early lactation to meet the high demands for milk secretion, and are in negative calcium balance. • Ewes fed adequate calcium in mid and late lactation are able to replenish the depleted calcium stores. • Therefore, a mineral mixture, balanced with calcium and phosphorus, should be available to ewes throughout gestation and lactation. • Hypocalcemia (milk fever) is a significant and sometimes fatal disorder of ewes during late pregnancy and early lactation. • Sheep are the most susceptible livestock to copper toxicity. • Contamination of sheep feed with copper (from poultry or swine feed with high copper added as a growth promoting), or grazing sheep on pastures fertilized with manure from swine or poultry fed high copper diets, may lead to outbreaks of copper toxicity.

Minerals for Cats and Dogs

• Minerals are inorganic elements that are essential for metabolism. • Minerals play a vital role in maintenance of the skeleton and teeth, nerve impulse transmission, muscle contraction, cell signaling, and maintenance of acid - base balance. • Problems with mineral imbalances in companion animal nutrition can greatly affect the availability of other nutrients. • Experimental evidence is available for the essentiality of 11 minerals by dogs and cats (NRC, 2003 ). • Of practical interest in pet foods are calcium and phosphorus, magnesium, and zinc

Fur Life Cycle

• Mink and foxes have a characteristic annual life cycle. • In the Northern Hemisphere, the mink kits are born during a 3-week period from late April to mid May, whereas fox pups are born from early April to late June. • The average litter size at birth is about six to seven in mink and silver foxes. • In mink, increased litter size may be obtained by applying a flush feeding regime, comprising a 2-week period of moderately restricted feeding, followed by ad libitum feeding from 3 to 5 days before mating. • The polar fox has a remarkable reproductive potential with an average litter size of about 10, and occasional litters with more than 20 liveborn pups. • Large litters and rapid growth of the offspring make the lactation period very demanding for breeding mink and fox females. • The offspring are fully grown and the fur is mature in November or December at an age of about 6 months.

Copper

• Natural copper deficiency increases susceptibility of ruminant animals to disease. • Several studies have investigated effects of copper on immunity in ruminant animals. • It should not be surprising that copper supports immunity as it is associated with many proteins

LIFE CYCLE NUTRITIONAL CONSIDERATIONS of Cats and Dogs

• Nutrient requirements of dogs and cats can vary significant during the life time of the animal. • While increased demands for energy and nutrients occur during gestation, lactation, growth, and performance, geriatric animals and animals at maintenance generally have a decreased need for energy and nutrients. • Proper dietary management of companion animals through all life stages is necessary to maintain optimal health of the animal.

Diet of Dairy Cattle

• Nutritional management of the lactating dairy cow may be the most complex system worked with by livestock nutritionists. • In 2002, the average dairy cow in the United States produced approximately 27.7 kg (60 lbs) of milk daily. • If one assumes that this milk contained 3.6% of fat and 3.0% of protein, over 800 g of protein and 19 Mcal of NEL must be provided daily just to meet the milk requirements. • These nutrient concentrations will leave nothing for maintenance, gestation, or growth. • As recently as 1988, protein nutrition of the lactating dairy cow was based on crude protein (CP). • However, the most recent set of nutrient requirements (NRC, 2001) places emphasis on meeting the amino acid requirements of the cow. • As knowledge advances and technology increases, our understanding of the nutritional management of the dairy cow will also change.

Wool Production in Sheep

• Nutritional status affects the wool growth of sheep. • Although wool is essentially pure protein, the daily protein requirement for wool growth is only a small component of the total protein requirement. • However, microbial protein does not contain an adequate amino acid balance to support maximal wool growth. • Australian researchers demonstrated that post-ruminal administration of sources of methionine or high-quality proteins to sheep markedly stimulated wool production. • Utilization of sulfur amino acid-rich sources of non-degradable protein in sheep feeding, might be a feasible way of increasing wool production. • The main nutritional factor limiting wool growth is energy intake.

Omnivores

• Omnivores are animals that are less fastidious in their feeding behavior and consume a wide variety of animal and plant foods. Pigs, poultry and humans are good examples.

Measurement of Energy Metabolism

• On a practical basis, energy metabolism of animals is assessed by measuring some general aspect of metabolism. • For example, in the utilization of carbohydrates, lipids and amino acids as energy sources, oxygen is consumed and carbon dioxide, water and heat are end products. • All of these (except water) can be measured in animals confined in special chambers called respirometers. • The ratio of these gases (moles carbon dioxide produced/moles oxygen consumed), the respiratory quotient (RQ), gives an indication of the nature of the metabolic fuel being used. • During metabolism of carbohydrate the RQ is 1.0. • Fatty acid metabolism is associated with an RQ of 0.7. • The RQ for protein is between 0.7 and 1.0. • Heat production can also be measured, and used as an indicator of metabolic rate.

NUTRIENT REQUIREMENTS OF DOGS AND CATS

• Pets must be fed a diet that provides all of the essential nutrients in their correct quantities and proportions in order to maintain health through all stages of life. • As a result of advances made in companion animal nutrition in recent years, nutrient deficiencies are rare in companion animals today. • Guidelines of nutrient requirements for dogs and cats are necessary to ensure that commercial pet foods meet the needs of companion animals. • A number of governing agencies and organizations regulate the production, marketing, and sales of commercial pet foods in the United States. • Two agencies, the Association of American Feed Control Officials (AAFCO) and the National Research Council (NRC), make recommendations for nutrients needed in pet foods.

Estrous in Beef Cattle

• Polyestrus: cats, cows, and domestic pig, meaning that they can go into heat several times per year. - Seasonally polyestrous animals or seasonal breeders have more than one estrous cycle during a specific time of the year and can be divided into short-day and long-day breeders: • Short-day breeders: sheep, goats, deer are sexually active in fall or winter. • Long-day breeders: horses, hamsters and ferrets are sexually active in spring and summer. • Diestrous: Species that go into heat twice per year, dog. • Monoestrous species, such as bears, foxes and wolves, have only one breeding season per year, typically in spring to allow growth of the offspring during the warm season to aid survival during the next winter.

Mineral Requirements of Avian

• Poultry have high requirements for mineral elements. • In the case of broilers, the rapid growth rate increases requirements. • Also, modern strains of broilers have been selected for a very meaty conformation, putting a strain on the legs and other support systems. • Proper balance of various minerals, including calcium, phosphorus, zinc, copper, and manganese, and the electrolytes sodium, potassium, and chlorine, is necessary to prevent leg disorders such as perosis and tibial dyschrondroplasia. • The calcium requirement of laying hens is very high (3.4 percent of the diet) for eggshell formation. • Good eggshell quality is very important to egg producers; their profit margin can be lost with a high rate of broken or cracked eggs. • Thus for layers, close monitoring of eggshell quality is necessary.

Pet Food Sales

• Premium dog and cat food sales have experienced dynamic growth throughout the world, but economy and mid -priced foods continue to have a large customer base. • Consumers who are cost - conscious regard these foods as being of sufficiently high quality to ensure adequate nutrition of their pets. • In addition, many of these foods are formulated based on life stage/lifestyle concepts previously available only with the premium food sector. • As regards animal numbers, it was estimated that 67 million dogs and 65 million cats were owned by Americans in 2001 (Special report: Pet food profiles, 2002).There are over 400 breeds of dogs in the world, with U.S. registering agencies recognizing over 180 different breeds.

Aquaculture and Fish Feeding

• Production of fish in ponds and raceways requires artificial feeding and the preparation of commercial feeds by feed manufacturers. • Compared to the traditional livestock species, the nutritional requirements of fish have received little attention. • However, the rapid expansion of aquaculture has led to considerable interest in fish nutrition. The nutritional requirements of fish differ substantially from those of mammals. • Fish are poikilothermic, which means that their body temperature is not homeostatically maintained but fluctuates with water temperature. • The body temperature of a resting fish is at or near the environmental water temperature. Thus, the maintenance energy requirements of fish are lower than for mammals because they do not need to expend energy to maintain their body temperature. • As a result, feed conversion efficiency is very high, often being one unit or more of weight gain per unit of feed. • Another factor contributing to high feed efficiency is that pond-raised fish may consume considerable amounts of natural foods in the pond, which are not included in the feed efficiency calculation • Warm water fish and shellfish have optimal water temperatures of 25 to 30°C. Examples of common warm water fish are carp, catfish, milkfish, and tilapia; shrimp and prawns are examples of warm water shellfish. • There are both marine and freshwater shrimp species, and the term prawn refers to any large shrimp. • Coldwater species, such as salmon and trout (salmonids), have an optimal water temperature range of 10 to 15°C • In the feeding of fish, it should be appreciated that most fish occupy an ecological niche near the top of the food chain. • Most fish have evolved as carnivores; there are few omnivores or herbivores in the natural environment, particularly in the oceans. • The metabolism of fish is adapted to a diet high in protein and low in carbohydrate, as is true for terrestrial carnivores. Therefore, it is not surprising that fish diets are high in protein and low in carbohydrate.

Protein Digestion - Allo-enzymatic

• Protein digestion in ruminants can be subdivided into two phases: - (i) alloenzymatic digestion in the stomach (reticulorumen); - and (ii) autoenzymatic digestion in the abomasum and small intestine. A third, minor phase is alloenzymatic digestion in the hindgut. • Dietary protein can either be: - fermented in the rumen, - or can bypass rumen fermentation and be digested in the small intestine. Several factors influence the rumen degradability of proteins, such as their solubility, and nature of their physical structure. • The majority of amino acids taken up by RMO are not used directly for protein synthesis, but are deaminated and used as energy sources, giving rise to: - Ammonia; - Branched-chain VFAs; - Carbon dioxide; - Methane. • Rumen ammonia occupies a central role in nitrogen metabolism in the rumen. • Ammonia is the nitrogenous end product of bacterial fermentation of dietary protein. • It is also the starting point for microbial synthesis of bacterial amino acids and proteins. • Most rumen bacteria synthesize their amino acids 'from scratch', with ammonia as the source of the amino group. • Thus rumen bacteria can synthesize protein from any substrate which will yield ammonia in the rumen. • Non-protein nitrogen (NPN) sources such as urea, biuret and uric acid (from poultry excreta) may be converted by RMO into bacterial protein.

Protein Requirements of Horses

• Protein makes up a greater proportion of the horse's body than any other constituent, with the exception of water. • On a dry, fat-free basis, protein makes up 80% of the body composition. • Protein is a major component of muscles, organs, enzymes, and blood. • Growth and tissue turnover throughout life represent the greatest need for protein. • Age and activity determine the protein requirements. • The degree to which a particular protein source meets the requirements for horses is based on the digestibility of the protein, the combination of amino acids included in the protein, and the protein-to-energy ratio of the ration. • Variability in protein digestibility of pasture forages depends on the season and stage of growth. • The stage of growth, at which hay is cut, will have an important effect on the protein content of hay. As the forage matures, protein digestibility decreases. • In certain classes of horses (e.g., young, growing horses, late-gestation mares, and lactating mares), protein quality is very important. High-quality hay such as alfalfa, is a good source of protein, but much of the protein in forages will be digested in the hindgut, and absorption of essential amino acids must take place in the small intestine. • Lysine is the most limiting essential amino acid in the diets of horses. • When feeding growing horses, protein sources with high levels of lysine must be included in the diet. • Soybean meal contains 3.2% of lysine compared to mature coastal Bermuda grass hay with 0.3% of lysine. Alfalfa hay is a good source of protein with levels often reaching 20%. • There is an important relationship between protein and energy, and for growing horses the relationship has been extended to lysine-to-energy ratios. • Although microbial synthesis of protein occurs in the hindgut, the significance of this component of protein digestion is not fully known. • It appears the microbial protein synthesized in the hindgut, is mainly for the microbes. • Non-protein nitrogen (NPN) can be used as the key ingredient of protein nutrition in ruminants, but it is not efficiently utilized by horses, and therefore almost never included in the diets of horses. • Feeding high-protein diets is generally not a problem for adult horses. However, there are exceptions to this rule. • Endurance horses that race over great distances are not fed high-protein feeds or alfalfa hay. • Feeding excessive protein and calcium may increase frequency of urination and adversely affect fluid balance, as elevated levels of degradation products must be filtered through the kidneys. • Fluid balance and dehydration are serious concerns for endurance horses and other horses performing hard work in areas of high heat and humidity

Rabbit Protein

• Protein requirements are 16% for maximum growth and 18% for lactation. • Dietary protein quality is important, although microbial protein from cecal fermentation does make a significant contribution. • Cecal fermentation and cecotrophy result in the ability of the rabbit to use some NPN, but in most cases, the ingredients used (alfalfa meal, wheat middlings, etc.) contain adequate total nitrogen. • Dietary protein quality is particularly important for rapidly growing weanling animals.

Nitrogen Metabolism in the rumen

• Proteins and other nitrogenous compounds can be digested (degraded) in the rumen by rumen microorganisms (RMO), with the conversion of dietary protein to microbial protein. • The rumen microbes (mainly bacteria) synthesize proteins which are ultimately used by the host animal when the microbes are digested. • It is important to bear in mind that the synthetic activities of the RMO are for their own benefit; there is not a higher calling that they are doing anything to benefit the host. • The RMO have fortuitously found themselves in an environment that is: - warm, - moist and anaerobic, - with a continual influx of food; - and a continual removal of their waste products. Fortunately for the ruminant, it benefits from these 'parasites' by being able to digest them and utilize them as a source of protein.

Proteins and Amino Acid Requirements for Cats and Dogs

• Proteins provide amino acids that cannot be made by dogs and cats (essential amino acids) but are required for synthesis of body proteins (NRC, 2003). • These include: - arginine, histidine, - isoleucine, leucine, - lysine, methionine, - phenylalanine, threonine, - tryptophan, valine. • Proteins also provide non-essential amino acids needed for dogs and cats in various physiological states (e.g., maintenance, growth, gestation, lactation). • Apparent total tract digestibility of protein is similar in dogs and cats for highly digestible proteins (NRC, 2003). • For dry or canned dog or cat foods, dogs have a protein digestibility approximately 5% to 8% higher than that of cats. • This may be a result of the shorter length of the small intestine relative to body size in cats versus dogs. • The protein requirement is the minimum intake of dietary protein that promotes optimal performance. • Criteria most often used to evaluate performance when determining protein requirements of dogs and cats are nitrogen balance and growth rate. • The cat has a higher dietary requirement for protein than does the dog because of its increased needs for maintenance of normal body tissue, not its increased needs for growth. • The higher protein requirement for maintenance in the cat results from the inability of the nitrogen catabolic enzymes in the cat's liver to adapt to changes in dietary protein intake. • Also in the cat, enzymes involved in nitrogen catabolism function at relatively high rates of activity, causing the cat to catabolize substantial protein after each meal, regardless of the dietary protein content. • The cat has limited capability to conserve nitrogen from the body's general nitrogen pool, so the only alternative that ensures adequate conservation of body protein stores is consistent consumption of a diet containing high concentrations of protein.

Rabbit Nutrition

• Rabbits are raised for a variety of purposes, including for meat, fur, and wool, and for use as laboratory animals. • Large numbers of rabbits are raised for exhibition and showing and many simply as pets. • Production of rabbit feed is a minor, but significant component of the manufactured feed industry • A number of generalizations can be made about rabbit feeds. • They should be pelleted because non-pelleted feeds are not well accepted by rabbits and give low growth rates and high feed waste. • Perhaps more than with other livestock, the feed has a major impact on the health of the animals. • Rabbits are quite susceptible to enteric diseases (enteritis, diarrhea) that have a major dietary component. • They are very sensitive to palatability factors and often refuse to consume a batch of feed even though it has the same ingredient specifications as the previous batch that they readily consumed. • Per unit of feed produced, feed mills probably have more complaints about rabbit feed than about any other feed.

Importance and function of minerals

• Represents 2 to 5% of the weight of the animal tissues • Acts as co-factors of enzymatic activity • Activate some hormones • Correlated with osmotic equilibrium • Correlated with the acid basic balance

Foregut Fermenters (Ruminants)

• Ruminants are classified in the order: • Artiodactyla, • suborder Ruminantia. • They are even-toed, hooved animals. • The term ruminant is derived from ruminare, a Latin word meaning to chew again. • Thus ruminants are animals which ruminate or 'chew their cud' by regurgitation of ingested material (rumination). • The foregut has probably achieved its highest complexity in anatomy and function in the ruminant animals. • Ruminants have a complex, compartmentalized stomach, characterized by one large compartment, the rumen, in which microbial fermentation of ingested feed occurs, in an anaerobic environment (fermentation is defined as anaerobic respiration). • Ruminants range in size from the tiny (1 kg) lesser mouse deer to the 1000 kg giraffe (Kay et al., 1980). • The four compartments are the rumen, reticulum, omasum and abomasum. • In the adult, and young animal with a functioning rumen, the rumen is the largest compartment. • It functions as a fermentation vat. • Rumen microbes, are primarily many species of anaerobic bacteria, and to a lesser extent protozoa, secrete enzymes which digest the consumed feed. • Because the rumen is an anaerobic environment, microbial fermentation cannot result in complete oxidation of carbohydrates to carbon dioxide and water. • Anaerobic fermentation is basically the glycolysis pathway by which glucose is broken down into pyruvic acid. • In the rumen, the microbes convert pyruvic acid to several short-chain organic acids, called volatile fatty acids (VFAs). • The VFAs are the main end product of rumen fermentation, and are the primary absorbed energy sources of ruminants. • The rumen is lined with projections called papillae. • The VFAs are absorbed into the papillae, in a similar manner as the absorption of nutrients into the villi of the small intestine. • Of major significance is the production of the enzyme cellulase by rumen microbes, permitting the digestion of fibrous feeds containing cellulose. • Other benefits of rumen fermentation include the synthesis of amino acids and water-soluble vitamins by rumen bacteria. • As a result, ruminants are largely independent of dietary sources of amino acids and water-soluble vitamins. • The rumen is continuous with the reticulum; they are often considered together as the reticulo-rumen. • The reticulum is lined with honeycomb shaped projections • Material exits the reticulo-rumen via the omasum. • The omasum is a small compartment containing membranous divisions called omasal leaves (omasum is Latin for book) function as a sieve, retaining material in the rumen until it has been degraded into small particle sizes • Fluids and small particles flow through the omasum to the abomasum, or true gastric stomach. • The abomasum contains large spiral folds in the fundus gland region. • Gastric secretions, such as pepsinogen and HCl, are secreted in the abomasum. The acidity kills rumen microbes in the digesta; they are then subject to digestion in the small intestine.

Protein Requirements of Beef Cattle

• Ruminants require dietary nitrogen to support rumen microbial growth, and absorbed amino acids to satisfy metabolic requirements for protein synthesis. • The minimum concentration of rumen ammonia necessary for optimal microbial growth and rumen fermentation in beef cattle has been estimated at 20 mg/100 ml of rumen fluid • The addition of a source of NPN (Non Protein Nitrogen) to the diet is beneficial only when rumen ammonia concentrations are below this level. • Various techniques have been developed to estimate the degree to which dietary nitrogen sources are partitioned, between fermentable nitrogen, and bypass protein so that the amount of NPN, such as urea, to be added to the diet to provide useful fermentable nitrogen can be calculated. • The main problem with such calculations is that the degree of ruminal degradation of a specific protein, is difficult to predict, as it is influenced by numerous factors such as forage level, feed intake level, particle size, and feed processing.

Rumination

• Rumination is the process whereby consumed feed is regurgitated and chewed to break it up into smaller particles. • Muscles at the base of the esophagus form a bolus of fibrous material, which is then propelled by muscular action to the mouth. • Mastication extracts the soluble cell contents, and mixes the remaining fibrous material with saliva. • Rumination time is greatest with high fiber diets, and is more important in roughage eaters than in concentrate selectors.

Stress-Susceptible Syndrome Swine

• Some breeds of swine have an inherited tendency to develop a rapid, fatal increase in body temperature (malignant hyperthermia) when subjected to normal management procedures such as transportation, exercise, mating, and parturition. • The meat from these pigs is pale, soft, and exudative (PSE syndrome). • The stress syndrome can be triggered by halothane anesthesia, which can be used to detect stress sensitivity in breeding animals. • Higher than NRC-recommended levels of vitamin E appear to have protective effects against the PSE-stress-sensitivity syndrome

Lipids for Swine

• Swine make efficient use of dietary lipids. • Linoleic acid is a dietary essential from which other unsaturated fatty acids (e.g., arachidonic acid) can be synthesized. • Theoretically, if pigs eat to meet their energy requirements, substitution of fat for carbohydrate should not increase performance or energy intake. • In general, so long as the diet is adequate in protein content, addition of fat tends to improve gains and reduce the ME required per unit of gain • High-quality animal and vegetable fat by-products are excellent high energy supplements, especially for growing-finishing pigs and lactating sows. • Fat increases diet palatability and energy intake, reduces dust in the swine buildings, and reduces wear on automated feeding conveyors. • The amount of fat added is limited, usually 1 to 4 percent, to prevent bridging in the storage tanks and feeders.

Vitamin Requirements for Beef Cattle

• The B-complex vitamins and vitamin K are usually synthesized in adequate amounts in the rumen, and vitamin D is obtained with exposure to sunlight. • Therefore, vitamins A and E are the major vitamins of concern. • Green forage is a good source of B-carotene. • Dietary vitamin A deficiency is most likely when cattle are fed high-concentrate diets, pasture or hay that is dry and sun bleached, or feeds that have been stored for extensive periods. • Vitamin A is often included in trace mineral mixtures, although some elements such as copper promote destruction (oxidation) of the vitamin. • The use of stable forms (vitamin A esters, e.g., retinyl acetate or palmitate) will help to reduce these losses.

NUTRIENT REQUIREMENTS of Horses

• The National Research Council (NRC) published minimum requirements in Nutrient Requirements of Horses in 1989. • In practice, many feed companies adjust these requirements when formulating diets to meet the optimum requirements for growth, reproduction, and work. • To take full advantage of the nutritional information available, owners should know the weight and body condition score of their horses and the weight of hay and grain being fed. • Knowledge of the estimated contributions of pasture throughout the year, is also an important component of understanding the nutrition of horses.

Rabbit Dietary Fiber

• The amount and type of dietary fiber is a major consideration in rabbit nutrition. • Indigestible fiber (cellulose + lignin, i.e., the ADF fraction) has important roles in maintaining adequate gut motility and preventing enteritis. • Digestible fiber (hemicellulose + pectins, i.e., NDF-ADF) functions in providing energy and promoting optimal populations of cecal microbes. • Optimal dietary fiber requirements are 15-20% ADF, 14-18% crude fiber, and a digestible fiber:ADF ratio of 1:3

Pig Diet Changes

• The diet changes made about every 1 or 2 weeks for increasing body weight are called "phase feeding." • At about 50 kg body weight, barrows are usually fed separately from gilts (split- sex feeding) because gilts are leaner and have higher amino acid requirements than those of barrows. • Baby pigs have the highest nutritional requirements, which decrease as growth proceeds. • Lactation is also a nutritionally demanding process for a good milking sow nursing a large litter. • Adult animals under maintenance conditions have the lowest nutrient requirements.

NUTRIENT REQUIREMENTS OF EXOTIC BIRDS

• The majority of cage birds are psittacine and passerines. • Psittacine are members of the parrot family (family Psittacidae) and include parrots, macaws, parakeets (budgerigars), lories, cockatiels, and cockatoos. • Passerines are members of the order Passeriformes or perching birds, and include finches and canaries • Many of the psittacine are altricial birds, meaning that they are physiologically immature at hatching and require a long period of intensive care by the parent birds or aviculturist. • The newly hatched young of altricial birds "look like embryos prematurely escaped from their shells", and are completely dependent on the parent birds for food, water, warmth, and care. • Adult psittacines and passerines are seed-eating birds. • They are commonly fed mixtures of "bird seed" such as sunflower, millet, sorghum, oat, corn, canary grass, pumpkin, rape, buckwheat, flax, and safflower seeds. • Fresh vegetable supplements and mineral-vitamin mixtures are often given.

Start of Digestion of CHO in Auto-enzymatic Animals

• The digestion of Carbohydrates (CHO), can start in the mount of some animal due the secretion by the salivary gland of alpha amylase. • Ruminants, Horse, Dog, Cat, and Birds do not have the alpha amylase enzyme, from the saliva. • Swine have the alpha amylase in the saliva, secreted by the salivary glands • The major enzyme involved in starch digestion is pancreatic amylase. • There are two amylases: one that cleaves alpha -1,4- bonds in random fashion while the other successively removes disaccharide units (maltose) from the polysaccharide chain • The action of amylases gives rise to a mixture of glucose, maltose and limit dextrins, which are the residues containing alpha-1,6- branch points. • Dextrins are digested by alpha-1,6- glucosidase. • Pancreatic amylase acts on starch granules in the lumen of the intestine. • The products of starch digestion diffuse into the brush border (unstirred water layer) where the final products are absorbed. • Monosaccharides are absorbed both by simple diffusion and by active transport against a concentration gradient. • A sodium-dependent glucose transport protein binds both glucose and Na+ at separate sites and transports them through the enterocyte plasma membrane, releasing them into the cytosol. • Active transport is an energy (ATP)-requiring process. • Various disaccharidases such as maltase complete the degradation of starch fragments to free glucose, which is then absorbed into the enterocytes • In the chicken, the chick at hatching has full development of its carbohydrate digestive enzyme activity, whereas this is not the case for species that consume crop milk (e.g. pigeons). • In contrast to the chicken, these crop-milk species develop digestive enzyme activity and diet shifts over the first few weeks of life • Similarly, in the pig and other mammals, the neonate initially consumes only milk, so at birth has a low activity of amylase, sucrase and other carbohydrase involved in digestion of plant-origin carbohydrates. • Only lactase is needed by the newborn mammal. • Development of digestive enzyme activity is stimulated by the consumption of solid feed by the young animal.

Energy Requirements for Horses

• The energy needs are the top priority of nutritional requirements for most classes of horses. • Other nutrients are no less important, but the bulk of the feed offered is to supply energy and that drives ration formulation. • Energy requirements for maintenance are fairly low for most horses; however, growth, lactation, and exercise increase energy requirements significantly. • Intense exercise such as race training and early lactation can cause energy requirements to increase up to 50% over maintenance needs. • Non-structural carbohydrates (NSC) are mainly digested and absorbed in the small intestine. • Pancreatic and intestinal enzymes digest these soluble carbohydrates to varying degrees. • One of the factors affecting NSC is the amount of forage in the diet. • Was found that when horses were fed a high-alfalfa diet, pre-cecal NSC digestibility was 46%. • However, when fed a high-grain diet, apparent NSC digestibility values were 71%. • Plasma glucose concentrations reflect dietary energy sources. • Plasma glucose concentrations are lower in horses than in simple stomach omnivores but higher than in ruminants. • Plasma glucose and insulin have received much attention recently. Glucose metabolism is influenced by energy partitioning in the diet. • Diets high in Non-Structural Carbohydrates, increase glycemic indexes when compared to diets high in structural carbohydrates, fat, and/or protein. • Blood glucose is absorbed into muscle and liver tissue and is stored as glycogen. • Pancreatic insulin is responsible for clearing glucose from the blood. • Insulin is thought to affect additional hormones such as growth hormone, insulin-like growth factors, and other hormones. • Current interest in nutrition and endocrinology suggest that different nutrients may affect metabolic pathways not only by enzymatic effects but also by altering hormonal profiles • Certain metabolic problems associated with high-grain diets such as tying-up and developmental orthopedic disease (DOD) have led to the creation of low-glycemic diets. • These diets contain highly digestible sources of fiber such as beet pulp and soybean hulls (not the outside hull but the seed coating). • The energy density of the feed is maintained by adding vegetable oil or high-fat rice bran. • The fat is usually included at 10% or less of the grain portion of the diet. • Unsaturated oils are typically the source of lipids added to horse diets. • Soybean oil and corn oil make up the majority of supplemented oil.

Mycotoxins and Swine

• The grains and protein supplements used in swine feeding are often contaminated with mycotoxins such as aflatoxin. • Swine are highly susceptible to acute aflatoxin poisoning, with severe liver damage a result. • Chronic toxicity with feeds containing 0.4 ppm or more aflatoxin is characterized by reduced gain and feed efficiency in mild cases, and severe liver and kidney damage with higher aflatoxin levels. • Systemic hemorrhaging is a common sign. • Increased dietary levels of methionine and protein help to protect against aflatoxin toxicity • Swine are highly sensitive to zearalenone, a Fusarium mycotoxin with estrogen activity. • Corn often contains zearalenone. • Hyper-estrogenic effects are seen, including swelling of the vulva and mammary glands, infertility, and vaginal prolapse. • Other common mycotoxins to which swine are often exposed are the trichothecenes, including vomitoxin,T-2 toxin, and diacetoxyscirpenol (DAS). • These toxins cause feed refusal and vomiting, and a number of other signs including diarrhea, hemorrhage, abortion, and neurological effects.

NUTRIENT REQUIREMENTS of Mink and Foxes

• The major nutrient requirements of mink and foxes have been tabulated by the NRC (1982). • Because the carnivore's digestive tract has a somewhat limited capacity, diets high in metabolizable energy density are needed. • Increasing the fat content in feed may benefit feed economy, because fat is a cheap energy source. • High levels of fat (up to 30 to 40 percent of dietary dry matter, and 50 to 60 percent of metabolizable energy) can be used in late fall, when muscle growth is declining and fat deposition is intensive. • Lower fat levels are used during the reproduction and early growth periods. • The protein requirement for growing mink is 35% up 13 weeks of age and 30% to 35% thereafter (NRC, 1982). • For growing foxes, the protein requirement is 28% to 30% up to 23 weeks of age and 25% from 23 weeks to maturity (NRC, 1982). • Data on essential amino acids have shown that methionine is commonly the first limiting amino acid in mink and fox diets. • A high methionine requirement during periods with intensive hair growth is related to the high content of sulfur-containing amino acids, especially cystine, in the fur. • Fish, fish by-products, eggs, and meat are sources of high-quality protein; however, some byproducts, such as chicken feet and low-quality meat-and-bone meal, have a poor amino acid balance and a low digestibility. • Plant protein sources like corn gluten meal, extruded peas, and soybean meal can be used in significant amounts in diets for mink and foxes. • Some nutritionist recommended that dehulled soybean meal be limited to less than 5 percent of the wet diet for mink. • The evolutionary adaptation to a low carbohydrate intake has not deprived the carnivores of the capability to utilize carbohydrates. • Mink and fox diets always contain some plant materials, as sources of nutrients, and partly as binders to achieve a suitable consistency of the wet diet and the feces. • NRC (1982) recommends that carbohydrates provide 15% to 25% percent of total ME for mink; foxes utilize carbohydrate better than mink • The main research efforts on minerals have involved iron. • Induced iron deficiency occurs with diets containing substantial amounts of raw fish of the cod family. • Marine fish contain high levels of trimethylamine oxide (TMAO) in their tissues. TMAO binds iron by forming insoluble iron oxide hydroxides in the digestive tract, preventing its absorption and inducing severe iron deficiency. • Mink that are fed raw fish of these species become severely anemic, and fur pigmentation is disturbed. The underfur developed during severe iron deficiency anemia is white or grey, causing the pelt to be almost worthless. • Mink ranchers have termed this the cotton fur syndrome. • Heat treatment of the fish and supplementation with suitable iron sources prevent the condition. • Iron deficiency impairs the enzymatic conversion of tyrosine to melanin in the hair follicle. • Copper is a cofactor also. Was observed that use of copper sulfate at feed additive levels in mink diets (100 to 200 ppm Cu) resulted in darker fur, presumably from increased melanin synthesis.

Hindgut Fermenters

• The microbial fermentation occurs in the digestive organs that follow the small intestine: the large intestine and cecum. • Examples of hindgut fermenters include proboscideans and large odd-toed ungulates such as horses and rhinos, as well as small animals such as rodents, rabbits and koalas • In many non-ruminant herbivores, the hindgut or large intestine (caecum plus colon) is enlarged and has a microbial population performing many of the same digestive functions that take place in the rumen. • Compared to the rumen, there are several nutritional disadvantages to the hindgut as a fermentation site. - Soluble nutrients, such as sugars, amino acids, vitamins and minerals, are absorbed in the small intestine. - Thus the composition of material entering the hindgut is less favorable for maximal microbial growth, than is the case in the rumen, where the microbes have all the nutrients in the ingested feed, as available substrate • The hindgut is a less efficient area for nutrient absorption. • In Ruminants - Products of rumen fermentation, including the microbes, are digested and/or absorbed in the rumen or small intestine. • Microbes in the hindgut are not subject to digestion (unless the feces are consumed). • The passage rate through the hindgut is more rapid than through the rumen, leading to a lower efficiency of fiber digestion.

Digestive Process in Ruminants

• The most fundamental aspect of allo-enzymatic digestion is the fermentation process. • Proteins are fermented in the rumen by microbial enzymes, and may be completely degraded to inorganic nitrogen (ammonia). • Microbes synthesize the amino acids, they require from ammonia and simple carbon compounds. • Much of the dietary protein is unavailable directly to the host animal. • The ruminant derives a high proportion of its amino acids from digestion of microbes in the small intestine • Similarly, much of the ingested carbohydrate is unavailable directly to the animal. • It is fermented by microbes in the rumen. • Waste products of bacterial digestion, a variety of short-chain organic acids (VFAs), are the primary absorbed energy source. • Thus, metabolism in ruminants is intimately associated with microbial digestion.

Cultural Systems and Fish

• The nutrient levels of fish diets are influenced by the cultural systems used. • With fish raised in ponds, insects, plankton, algae, and other natural food may provide a significant portion of the nutrient intake and satisfy the requirements for vitamins and pigmenting agents. • In some systems, such as carp production, the pond, rather than the fish, is fed. Ponds may be fertilized with manure or inorganic fertilizers to stimulate growth of plankton and algae, and the cultured fish or shrimp feed on these materials, especially in the early growth phases. • Fish reared in raceways are entirely dependent on the offered feed, and, therefore, their nutritional requirements are more critical.

Rabbit Nutrient Requirements

• The nutrient requirements of rabbits are influenced by their digestive tract physiology. • Rabbits have microbial fermentation in the cecum and consume the cecal contents (cecotrophy). • Cecotrophy, usually occurs once or twice per 24-hour period, generally at night; hence the common name "night feces" for the cecotropes. • Consumption of cecotropes provides a source of microbial protein as well as an adequate supply of all of the B vitamins. • Rabbit nutrition research has been quite limited as compared to that of most other domestic species.

HAIR GROWTH on Animals

• The only economically important product of fur animals is the pelt, so it is appropriate to briefly consider the physiology of hair growth. • The physiology of wool growth is very similar; these comments on hair growth are relevant to sheep and Angora goats as well. Hair follicles develop as extensions of the outer layer of the skin. At birth, an animal has its full complement of primary hair follicles; subsequent development of the hair coat depends mainly on nutritional and environmental factors. • At the base of the follicle is a highly vascular layer called the papilla, which provides the developing hair with nutrients. • The growth of the hair occurs from the matrix plate directly above the papilla. • The hair cells become cornified shordy after their formation, so the hair fiber, as it emerges from the skin, consists of dead cornified cells.

Animal Furs

• The principal animal grown commercially for its fur is the mink, which is produced mainly in Denmark and other Scandinavian countries, the Netherlands, China, the United States, Canada, and Russia. • To a lesser extent, polar foxes (blue foxes) and silver foxes are raised for their pelts, mainly in Finland, Norway, China, Russia, and Poland. • The production of other fur-bearing species such as Beaver (Nutria) and Chinchilla is very minor. • Mink and foxes are by nature carnivores and their natural diets are rich in animal protein and fat, and low in carbohydrate. • The farmed mink and foxes are usually fed diets containing animal sources such as fish by-products, either raw or converted into fish meal or fish silage, and byproducts from slaughterhouses. • These products are mixed with cereals, animal or vegetable fats, vitamins, minerals, and water to a moist diet in the consistency of raw hamburger. • There is a trend to reduced levels of protein and increased use of fats and precooked cereal grains to produce high-energy diets for mink and fox feeding. • Carnivores have a short intestinal tract, rapid rate of passage of ingesta, and minor microbial action in the gut, so they require easily digestible nutrient sources and a high content of metabolizable energy in the diet.

Caecal fermenters

• The rabbit is probably the best-known example of a caecal fermenter. • The hindgut of the rabbit functions to selectively excrete fiber, and retain the non-fiber components of forage for fermentation in the cecum. • Peristaltic action propels the fiber particles through the colon rapidly, whereas anti-peristaltic contractions of the haustrae of the proximal colon move the soluble nutrients and fluids 'backwards' into the cecum. • The digestive strategy of the rabbit and other small herbivores is to minimize the digestion of fiber, and to concentrate digestive action on the more nutritionally valuable nonfiber constituents • After the colon is emptied of hard faecal pellets, consisting primarily of fiber, the caecum contracts and the caecal contents are squeezed into the proximal colon. • Mucin is secreted by goblet cells, producing caecal material covered with a mucilaginous membrane • This material, known as caecotropes or 'soft faeces', is consumed by the animal directly from the anus. • Consumption of caecotropes (caecotrophy) provides the animal with a means of more efficiently digesting the products of caecal fermentation, digesting the microbial protein, and obtaining microbially synthesized B vitamins • Because caecal fermentation is an adaptation for utilizing fibrous diets without the encumbrance of an overly large gut, most caecal fermenters are small animals. • The largest include the koala (about 10 kg) and the capybara (about 50 kg). Small animals have a much greater relative metabolic rate and energy requirements than do large animals

Rabbit Minerals

• The rabbit is very efficient in absorption of calcium. • Excess calcium is excreted in the urine rather than by the fecal route as is typical of most species. • Rabbit urine often has a cloudy appearance due to its high content of calcium carbonate. • Diets with high (40 to 60%) levels of alfalfa meal, usually contain excess calcium, which is excreted in the urine. • Both deficiency and toxicity of vitamin A cause reproductive problems, including resorbed fetuses, abortion, hydrocephalus (enlarged head containing fluid), and small, weak kits at birth. • Deficient and toxic dietary vitamin A levels have not been well defined but are in the region of 5,000 and 70,000 IU/kg diet, respectively. • Rabbit diets are typically quite high in alfalfa, which is a good source of B-carotene. • Animals convert B-carotene to vitamin A, but do not form a toxic level of vitamin A. • However, when synthetic vitamin A is added to a diet rich in carotene, a relatively low level of synthetic vitamin A may be enough to induce a toxicity state. Rabbits have very low vitamin D requirements. Excess vitamin D can cause massive mineralization of the soft tissues such as arteries, kidneys, and lungs

Foregut Versus Hindgut Fermentation and Body Size

• The relative efficiencies of ruminant and nonruminant digestion are influenced by body size and the abundance and quality of plant material. • Among herbivores in general, the ruminants dominate in numbers, in the intermediate body-size range. • Very small (e.g. rabbits) and very large (e.g. elephants) herbivores, are mainly non-ruminant herbivores • Small non-ruminant herbivores are better able to utilize high quality forage than small ruminants because of direct digestion without fermentation, combined with coprophagy. • As the body size of ruminants decreases, fermentation of forages can no longer meet the increasing (per unit of weight) energy requirements. • With very large ruminants, however, insufficient fibrous feed can be ingested to meet the energy requirements of a large body mass through fermentation byproducts.

Energy and Protein Requirement for Sheep

• The requirements for energy and protein are discussed by NRC (1985). • Utilization of protein and energy is similar to that described for beef cattle. • Because their browsing ability allows them to select a more nutritious diet when availability of feed is not limiting, sheep and goats may perform better on a "rough" pasture than cattle. • However, this should not be construed to mean that they have lower nutrient requirements and can survive on poorer quality feed. • The opposite is true: these smaller ruminants have higher nutrient requirements and require higher-quality feed than cattle. • Therefore, when they are fed mixed or pelleted feeds or conserved forage (hay or silage), which reduces their ability to select the more nutritious components, they require higher quality feed than cattle. • After breeding, ewes in the early stages of pregnancy are fed just above maintenance conditions for approximately 3 months on good pasture or hay. • Ewe lambs bred to lamb at 12 to 13 months in age, and need to be fed at higher levels of nutrients to allow for continued growth as well as fetal development. • Lambing is a critical period for the sheep producer. • The entire annual economic return from a ewe (except for wool) depends on whether her lamb(s) survives. • It is critical that the newborn lamb receives colostrum in the first hour of life. If it does not, it becomes progressively weaker, is unable to suckle, and dies of starvation. If a lamb is too weak to nurse, it should be given colostrum by stomach-tube. • In order to provide for the needs of the suckling lambs, proper feeding during lactation is important. • Milk production in the ewe peaks at 3 to 4 weeks following lambing. • Ewes nursing singles produce more milk than the lamb will consume so they adjust production downward. • Ewes suckling twins produce 30 % to 50 % more than ewes with singles. • Ewes with triplets produce 30 % more than those raising twins. • Ewes suckling more than one lamb during early lactation have the greatest nutritional needs of any time during the production cycle .

PRINCIPLES OF ZOO ANIMAL NUTRITION

• The role of zoological gardens is no longer simply the exhibition of exotic animals, but increasingly one of propagation and survival of endangered species. • The rapid decimation of the natural environment in tropical areas of Africa, Central America, South America, and Asia imperils the survival of many species. • Environmental changes and human population growth, with consequent habitat alteration, impact nutritional resources of even well-managed lands such that populations of many species may not be viable or sustainable in nature. • For some species, intensive management in parks, reserves, and zoos may represent a long-term survival option; this puts a tremendous responsibility on the nutritionists involved, for the survival of a species may rest in their hands.

The Rumen Microbes

• The rumen microbial population is responsible for much of the total digestive activity in ruminants, particularly in roughage eaters. • The main microbes are bacteria and protozoa, although yeasts, fungi and phages are also found in small numbers • Rumen bacteria can be broadly considered as starch digesters (amylolytic) and cellulose digesters (cellulolytic). • Examples of some of the main genera of rumen bacteria are Bacteroides, Ruminococcus, Butyrivibrio, Selenomonas and Methanobacterium. • An example of an amylolytic organism is Bacteroides amylophilus while Bacteroides succinogenes is cellulolytic. 4 key services to the cow 1) Amino Acid Production 2) Protein Production 3) Synthesis of B-vitamins 4) break down of cellulose • Comparative studies indicate that the rumen microbes are similar among different species of ruminants, and between wild and domestic animals. • The rumen protozoa make up a substantial (about 40%) part of the total microbial mass of the rumen. • However, their metabolic contribution appears to be much lower than their mass would suggest. • Most of the rumen protozoa are ciliated, although there are a few flagellated types • The numbers and types of rumen protozoa are considerably influenced by the type of diet. • Concentrate selectors tend to have a simple protozoal population, while mixed feeders have a more diversified fauna. • For example, protozoal concentrations in African wild ruminants tend to be higher in concentrate selectors (giraffe, dik-dik) followed by intermediate feeders (impala, eland, Grant's gazelle) and lowest in grass and roughage

Protein Needs of Fish

• The values are much higher than for livestock diets. • Because fish utilize carbohydrates poorly, the concentration of carbohydrate in the diet is low. • Consequently, protein and fat percentages are high. • A considerable portion of the dietary protein is used as a source of energy. • Protein is used more efficiently as an energy source in fish than in mammals and birds because the nitrogen from amino acid deamination is excreted as ammonia via the gills. • In mammals and birds, energy is required to synthesize urea or uric acid from the deaminated nitrogen. • On a percent-of-diet basis, the essential amino acid requirements of fish are higher than for swine and poultry. • Because of the high-protein content of fish diets and the high essential amino acid requirements, animal protein sources provide a large part of the protein in fish diets. • Fiber level of the meal is important as excess fiber reduces pellet stability and reduces energy density of the diet. • Levels of 25 to 30% dehulled soybean meal have been demonstrated to give good performance in shrimp. • Reducing the reliance on fish meal in shrimp feed will reduce cost and lower the possibility of diet-transmitted pathogens. • Formulation on a digestible amino acid basis and the use of ideal amino acid ratios will reduce nitrogen loading of pond water and effluent. • Use of phytase enzyme will have a beneficial impact on phosphorus levels in water if methods of application can be found to increase enzyme stability and reduce possibility of leaching • Ingredients such as porcine plasma protein, soy protein concentrate, and partially hydrolyzed vegetable protein may have future utility as attractants and nutrient sources. • Fish feeds are typically high in protein content, and modern aquaculture facilities have fish at high stocking densities . These conditions favor the build -up of nitrogenous wastes in the water, causing toxic reactions in the fish. • Fish excrete excess nitrogen as ammonia . Once in the water, ammonia undergoes bacterial oxidation to form nitrite . • Both ammonia and nitrite are toxic to fish, causing growth inhibition and mortality. • They stimulate secretion of stress hormones such as corticosteroid hormones that impair immune function and cause increased susceptibility to disease .

Horses

• The vast majority of the research published on horse nutrition has appeared in scientific journals in the last 30 years. • Nutritional studies on most other livestock species have been published in significant numbers for over 75 years. • Although excellent progress has been made in horse nutrition, there is still a great deal of work to be done. • Many of the published requirements are extrapolated from studies in other species or developed from the limited research available in horses. • Research in horses is complicated by the need to know the nutritional requirements for a variety of athletic endeavors. • Exercise, changes the nutrient requirements for energy, protein, calcium, phosphorus, magnesium, trace minerals, and vitamins. • Requirements for production (i.e., reproduction and growth) must also be fine-tuned. • Production agriculture is certainly important to the horse industry; however, horse production and general livestock production diverge somewhat when the ultimate goals are considered. • The goal of most horse owners is to produce horses capable of exceptional athletic performance, over an extended period of time. • Rapid weight gains in growing animals are known to be counterproductive, to the long-term soundness and athleticism of horses. • Horse producers also often view least-cost rations and other common livestock management systems with caution • Horses are marketed and treated as individuals throughout much of their lives. • The value of individual horses becomes of primary importance. • Horses that are shown or raced usually increase in value with additional training, and such horses generally have value as companions. • The real or perceived value of horses often leads owners to make management decisions about feed and supplements based on the idea of "protecting their investments." • Supplement manufacturers direct marketing concepts toward enhancing performance or protecting the health of the horse. • Some of the supplements are useful, some are useless. • One important aspect of an education in applied animal sciences is the ability to sort out the advantages and disadvantages of the vast array of nutritional supplements available for horses

Vitamin Requirements of Horses

• The vitamin requirements of horses have not been well studied. • Most of the data available is on vitamins A, D, and E. • These are probably the major vitamins of dietary importance, as the B vitamins and vitamin K are synthesized by gut microbes. • Horses grazing good-quality pastures generally do not require vitamin supplementation (NRC, 1989).

Ruminant Wild Diets

• There are considerable differences in the lipid composition of wild ruminants compared to modern sheep and cattle. • Wild ruminants are generally much leaner, having lower quantities of depot fat and intramuscular fat (marbling). • A greater proportion of the tissue lipid of wild ruminants consists of structural lipids such as phospholipids in cell membranes.

Types of Hair Follicles

• There are two main types of hair follicles, the primary and the secondary follicles. • The primary follicles produce the longest type of hair, the guard hair, and the shorter, intermediate guard hairs grow from lateral primary follicles, while the underfur grows from secondary follicles. • The primary follicles are arranged as a triad, with a central follicle and two laterals. The primary follicles have an arrector pili muscle, which allows erection of the guard hair during fright or anger and, under cold conditions, increases insulatory properties by trapping air in the coat. The development of the winter coat is due to the action of melatonin, a hormone produced by the pineal gland. • Melatonin production and secretion are regulated by day length (photoperiod). • The hair coat undergoes a growth cycle. • At one stage in the cycle, it reaches a state referred to as the prime condition. • The pelt must be harvested when the fur is prime. • If the pelt is not prime, the garment manufactured from it will shed hair and be unattractive. • A hair undergoes three distinct growth phases in which periods of active growth alternate with resting periods. These periods are the anagen, catagen, and telogen phases. • During the anagen phase, the hair shaft undergoes rapid growth. The follicle is embedded deep in the skin. Pigments are actively synthesized in this phase and move up the hair shaft as it grows. The hair pigment cells, called melanocytes, can be seen as dark-colored areas on the leather side of an un-prime pelt. • As the growth cycle proceeds, the hair follicle shortens until its base is located just below the sebaceous gland in the upper layer of the skin, and the papilla atrophies. These processes occur in the catagen phase. • During the telogen phase, the hair is in a resting state, and the pigment cells have been drawn up into the hair shaft. At this stage, the pelt is prime.

Aquaculture

• There is increasing interest in aquaculture (fish farming) as a means of producing high-quality human food. Aquaculture is the fastest growing sector of the world feed market, and consumption of cultured fish and seafood is increasing dramatically • The main types of commercially farmed fish in North America are carp, catfish, milkfish, rainbow trout, salmon, shrimp, and tilapia. • During the 1980s and early 1990s, channel catfish production expanded rapidly in the southern United States, and salmon production expanded in coastal British Columbia. • More recently, carp, catfish, milkfish, shrimp, and tilapia production have expanded massively in China and Southeast Asian countries. • Cultured shrimp are major export earners in Thailand, Indonesia, and Vietnam. • Marketing of fish in contrast to poultry and swine is highly fragmented, as there is a wide array of finfish, mollusks, and crustaceans involving both aquaculture and wild catch. • 90% of world production of Aquaculture is in Asia. • China is by far the leader, China produces mainly carp and tilapia grown on a sustainable basis in small holdings. • Fish are collected and sold in traditional wet markets by third parties. Although Chinese aquaculture lacks capital and organization, the use of processed feed has recently caught the attention of the more progressive growers as a way to increase profit. Aquaculture feed production is expanding rapidly in China • Shrimp and salmon, because of their relatively high value among the cultured fish species, stand out for their potential to be grown the way broiler chickens are, that is, in vertically integrated businesses. • Business integration and technological development will lead the way for cultured aquatic species to become major protein sources in the human diet.

Sodium, Potassium, and Chloride Minerals

• These 3 minerals works together with phosphate ions, and bicarbonate ions. • Regulate the osmotic pressure and acid-basic homeostasis. • Control in the absorption of nutrients in the cells, and the metabolism of water.

Limiting Amino Acids

• These amino acids are also called limiting amino acids and they are: - lysine, - threonine, - methionine, - tryptophan. Limiting amino acids are found in the shortest supply from incomplete proteins. Incomplete proteins are those found in plant food sources Why Lysine?? • Very low endogenous syntesis; • Transamination do not happen in the body (Lysine, Threonine, Proline, and Hydroxyproline); • The metabolism is correlated with body protein growth; • Have slow turnover; • Ileum digestibility is very correlated with biological availability of lysine; • Very accurate analyzes methods is established; • The animal requirements are already very well know in all phases of animal growth in many species of animals for production.

Vitamins for Dogs and Cats

• They are not used for energy or incorporated into cells. • They are most commonly used as enzyme cofactors. • The diverse range of abnormalities noted with vitamin deficiencies and excesses reflect the diverse metabolic functions of vitamins. • Fat-Soluble Vitamins Fat-soluble vitamins include vitamins A, D, E, and K. • These vitamins are absorbed in the intestine with dietary fat. • Therefore, any disturbance in normal lipid metabolism will adversely affect the fat-soluble vitamin status of the animals as well.

Turkey Diseases

• Turkeys are affected by a number of disorders that have a nutritional component. • Leg weakness disorders are associated with deficiencies of nutrients involved in bone formation, including calcium, phosphorus, vitamin D3 , choline, biotin, folic acid, manganese, and zinc. • Enlargement of the hock joint may occur with deficiencies of niacin, biotin, vitamin E, or zinc. • Footpad dermatitis is typical of biotin deficiency. Diets causing sticky droppings, such as with barley or poorly processed soybean meal, may cause droppings to adhere to the feet and cause dermatitis. • Pendulous crop, caused by yeast proliferation in the crop, may occur with diets high in fermentable carbohydrate. • The distention of the crop associated with gas production from the fermentation may interfere with passage of ingesta from the crop to the proventriculus, causing the pendulous crop condition. • The disorder can be treated with a fungal inhibiting antibiotic. • Ascites, or fluid accumulation in body cavities, has been observed with high salt intakes. • Selenium deficiency also causes an edematous condition, exudative diathesis. A selenium deficiency seen in turkeys is gizzard myopathy, or degeneration of the gizzard.

NUTRIENT REQUIREMENTS OF TURKEYS

• Turkeys are raised for meat. • Strains have been selected for rapid growth and efficient meat production. • Essentially all of the commercially produced birds are white, whereas in the past the bronze-colored breeds predominated. • There is a niche market for so-called heritage breeds of turkeys, which are traditional breeds that have fallen by the wayside with the development of "industrial" white birds. • Turkey meat has changed from being a seasonal dish (Thanksgiving and Christmas) to having year-round consumption, with new products such as turkey ham contributing to this trend. The consumer demand for white meat has also increased turkey consumption. • Young turkey poults have a higher protein requirement than chickens. • Starter diets (zero to 4 weeks) should contain 28% crude protein. • The protein content can be reduced by approximately 2% during each 4- week period, up to a market age of approximately 20 weeks. • Turkeys are sometimes raised outside on ranges, but the nutritional contribution of grass, insects, and so on that they obtain is usually of little significance.

Unique Amino Acid Requirement For Cats

• Two unique amino acid requirements occur for the cat: - (1) the cat does not have the ability to synthesize adequate arginine for normal functioning of the urea cycle and protein synthesis; - (2) the cat has a dietary requirement for taurine, an amino sulfonic acid. • Cats develop severe hyper-ammonemia within hours of consuming a single arginine-free meal. • Clinical signs include vomiting, muscle spasms, ataxia, sensitivity to touch, and tetanic spasms, leading to coma and death. Reasons for this include the fact that the cat is unable to synthesize de novo ornithine, an arginine precursor in the urea cycle. • Taurine • Taurine: is found as a free amino acid in tissues (brain, heart, skeletal muscle) or as a constituent of small peptides. • It is synthesized by most mammals from methionine and cysteine during normal sulfur amino acid metabolism. • The myocardium and retina contain high concentrations of free taurine (100 to 400-fold greater concentrations than those found in plasma). • The cat has a high metabolic demand for taurine as it uses only taurine for bile salt formation and cannot convert to conjugation of bile acids with glycine when the taurine supply is limited. • Taurine deficiency in cats results in feline central retinal degeneration and blindness, dilated cardiomyopathy and heart failure, inadequate immune response, poor neonatal growth, poor reproduction resulting in a low number of fetuses, resorptions, abortions, decreased birth weight and low survival rate of kittens, and congenital defects including hydrocephalus and anencephaly

Protein and Amino Acid Requirements of Swine

• Under practical conditions, lysine, methionine, tryptophan, and threonine are the main amino acids of concern. • However, valine may also become limiting in very low protein diets. • Metabolically, the L-isomers are required, although in some cases the Disomer is used by being converted in the liver to the L form. • Thus, the relative potencies are: - D-methionine, 100 percent of the L form; - D-tryptophan, 60 to 70 percent to the L form; - D-lysine, 0 percent; - D- threonine, 0 percent. • Lysine is usually the first limiting amino acid in diets for swine of all ages. • Methionine and threonine may also become limiting in Phase 1 and 2 nursery diets that contain supplemental blood by-products as protein sources. • Soybean meal is the plant protein supplement of choice in the United States. • The simple corn-soybean meal diet supplemented with minerals and vitamins has become the standard against which all other more complex diet formulations for growing-finishing pigs and sows are evaluated by economics and performance. • For pigs at weaning, spray-dried animal plasma is an expensive supplement that is generally added at 4 to 6 percent of the first (Phase 1) postweaning diet because it stimulates feed intake, enhances immunity, and improves growth performance of pigs weaned at 14 to 17 days of age

Protein Requirements of Dairy Cows

• Until recently, when discussing ruminant protein nutrition, crude protein was the unit of choice. • This was based on the understanding that fermentation in the rumen would modify the proteins fed by converting them into microbial protein. • Therefore, dietary composition was believed to have little impact on the amino acids that were digested by the cow • Lysine and methionine have been identified as the first two limiting amino acids, for milk production under, most production settings. • Because of this observation, efforts to predict the flow and absorption of these amino acids, at the small intestine along with methods to increase their flow and absorption, have become a part of dairy nutrition consideration.

The Digestive System

• Vertebrates have evolved more complex digestive systems to adapt to their dietary needs. • Some animals have a single stomach, while others have multi-chambered stomachs. • Birds have developed a digestive system adapted to eating un-masticated food

Vitamin D for Cats and Dogs

• Vitamin D is required for calcium and phosphorus metabolism and homeostasis by increasing circulating calcium and phosphorus. • This increase allows for bone remodeling and maintenance of extracellular calcium concentrations. • Most animals, including the dog, are capable of synthesizing vitamin D3 , cholecalciferol. • Vitamin D toxicity results in calcification of the soft tissue. If the animal consumes high concentrations of vitamin D for a long period of time, skeletal abnormalities can develop in growing animals. • Vitamin D deficiency in companion animals will result in rickets in growing animals and osteomalacia in adult animals.

Vitamin E for Cats and Dogs

• Vitamin E functions in the body as the major lipid-soluble antioxidant that prevents peroxidation of lipids in plasma, red blood cells, and tissues. • The active form of vitamin E is a-tocopherol. • Vitamin E works synergistically with selenium to neutralize free radicals. • Vitamin E toxicity and deficiency are extremely rare in companion animals. Deficiency of vitamin E is associated with skeletal muscle degeneration, poor reproduction, and impaired immune responses.

Vitamin K

• Vitamin K is a group of structurally similar, fat-soluble vitamins found in foods and in dietary supplements. • The human body requires vitamin K for complete synthesis of certain proteins that are needed for blood coagulation or for controlling binding of calcium in bones and other tissues. • In allo-enzymatic animals the synthesis is in the rumen, by the bacteria. • In auto-enzymatic animals the synthesis is in the large intestine. In that case only can be used if exist coprophagy. • Deficiency: problems with blood coagulation.

Vitamin K for Cats and Dogs

• Vitamin K is necessary in the body for normal blood clotting. • Bacteria in the intestine can synthesize menadione, the active form of vitamin K, so the dietary requirement is very low. • Vitamin K deficiency and toxicity are very rare in companion animals. • Signs of vitamin K deficiency include development of ulcers and an increased time for blood clot formation.

Vitamin Requirements of Swine

• Vitamin requirements expressed as a percentage or amount per kilogram of diet for growing swine Commercial vitamin premixes are formulated with crystalline or synthetic vitamins to provide specific amounts of the vitamins known to be limiting or deficient in the feed ingredients. Premixes for growing-finishing swine fed grain-oilseed meal diets in confinement usually contain the fat-soluble vitamins A, D, E, and possibly K. Vitamin K may be added because of the frequent occurrence of mold toxins in cereal grains that interfere with the blood clotting mechanism in swine. • The water-soluble vitamins required by growingfinishing pigs include riboflavin, niacin, pantothenic acid, and vitamin B12. • Vitamin B12 is provided because animal protein ingredients, a natural source of B12, may not be used in growing-finishing diets. • A common belief is that pigs exposed to their feces meet part of the Bcomplex vitamin requirements by coprophagy and have lower vitamin requirements than those raised on slatted floors. • Folic acid is particularly important in sow nutrition. • Folates function as coenzymes in nucleic acid synthesis, so the requirement is highest during periods of rapid cell division, such as during rapid growth of the fetuses.

Water for Dogs and Cats

• Water • Water has several functions in the body. • It acts as a solvent that facilitates intra and extracellular reactions, a transporter for nutrients and waste products, a regulator of body temperature, and a lubricator of joints and organs. • Adequate water intake is required for normal digestion and metabolism of food. • Approximately 70% of lean body mass is water, and a loss of only 10% of body water can result in death. • All animals experience three major routes of daily water loss. • The majority of water is lost during urinary excretion. • Water excreted with feces accounts for a smaller portion of water loss. • The final route of water loss is from the lungs through evaporation. • Evaporation is important for dogs and cats for the regulation of body temperature in hot weather. • Panting reduces body temperature, but water losses due to evaporation can be large during this time. • Daily water consumption must make up for normal water losses. • Three sources of water intake exist for dogs and cats: - metabolic water, - water present in food, - voluntary water consumption. • Metabolic water is water produced during the oxidation of energy-containing nutrients in the body. • The production of metabolic water is small, ranging from 5% to 10% of the total water intake of the animal. • The amount of water voluntarily consumed by the dog and cat depends on the amount of water present in the food. • Other factors affecting voluntary water intake include environmental temperature, exercise, physiologic state, and overall health. • The water requirement of cats and dogs, expressed in milliliters (mL), is believed to be equal to two to three times the dry-matter intake of food, expressed in grams. • The best method of ensuring adequate water intake is to provide the animal with fresh, clean water at all times, regardless of dry-matter intake.

Water Requirements of Dairy Cattle

• Water intake is often overlooked and misunderstood when feeding most species of livestock. • Dairy cattle are no exception. However, water intake is extremely important to the dairy cow if one considers that milk is approximately 87% water. • Obviously, limiting water intake by lactating cows will have a negative impact on milk production. • Water requirements can be met through three sources: drinking water, metabolic water, and water in feed. • Many factors will influence the cow's desire to consume water. • As has already been mentioned, milk production requires large amounts of water and does play a role in determining water intake. • Similarly, dry-matter intake (DMI) appears to positively influence water intake. • Whether this is due, to an increased need for water as solvent for metabolic reactions, to solvent for microbial fermentation, or to increased losses of water through increased fecal and urinary turnover, is not completely clear, but the relationship between DMI and water intake is quite strong. • Environmental factors such as temperature, humidity, and wind speed are also factors in determining water intake.

Water for Swine

• Water is required in a larger quantity by swine than any other nutrient. • Water functions as a structural element by giving form to the body through cell turgidity, in temperature regulation, transport of nutrients from the site of absorption to the cells of the body tissues, and removal of waste products from cells. Water has a role in facilitating virtually every chemical reaction that takes place in the body, plus lubrication of the joints as a component of synovial fluid, and cushioning for the nerves as cerebrospinal fluid. The water content of the body tissues is highest at birth and declines with age as the percentage of body fat increases, with a significant inverse relationship between body water and fat content • The body water content of the pig remains remarkably constant at a given body weight and fat content. • Swine lose body water mainly by urination, followed by defecation, respiration and by evaporation from the skin even though the sweat glands of the pig remain dormant. • Therefore, it is essential that swine are provided ad libitum access to fresh, high-quality drinking water to maximize feed consumption and growth rate

Water-Soluble Vitamins for Cats and Dogs

• Water-soluble vitamins are absorbed either by passive diffusion or sodium-dependent active transport systems. • The water- soluble vitamins required for dogs and cats are the nine B vitamins: thiamin, riboflavin, niacin, pyridoxine, pantothenic acid, biotin, folic acid, cobalamin, and choline. • These vitamins are involved in the metabolism of energy and tissue synthesis. • Deficiencies and toxicities of B vitamins are extremely rare in companion animals.

Weaning Swine Diets

• Weaning is a critical period for the young pig. • The stress of weaning accompanied by dietary changes makes the animal very susceptible to post-weaning diarrhea (enteritis).

Metabolic Disorders

A number of metabolic disorders have their basis in disturbances in energy metabolism. • These include: - diabetes, - metabolic syndrome, - ketosis. Besides these, other aspects of energy metabolism, include metabolic events in: - obesity, - longevity

Laminitis

Inflammation of the laminae of the foot - the soft tissue structures that attach the coffin or pedal bone of the foot to the hoof wall. The inflammation and damage to the laminae causes extreme pain and leads to instability of the coffin bone in the hoof.

innate vs adaptive immunity

Innate / Natural Immunity (non-specific responses) 1st line - skin, mucous membranes and secretions, normal flora 2nd line - innate immune cells, inflammation, complement, antimicrobial substances Adaptive / Acquired Immunity (specific Responses) 3rd line - Specialized lymphocytes - B cells (produce antibodies), T cells - Helper T cells and Killer T cells

Ketosis

Ketosis is a metabolic disease, in which excessive quantities of ketone bodies are produced. • It commonly occurs in starvation when body lipid is mobilized, and is a frequent condition in domestic ruminants (twin-lamb disease or pregnancy paralysis in sheep; ketosis and downer cow syndrome in dairy cattle). • A critical factor in the development of ketosis is insufficiency of glucose for brain metabolism. • Glucose is specifically required as an energy source by some tissues. • For example, the brain and central nervous system require glucose, although ketone bodies can be used to some extent. • The energy requirement of the brain under normal circumstances is met almost entirely from the metabolism of glucose. • The blood-brain barrier limits the penetration of large molecules, such as lipids, into the brain. • As a result, the brain depends on glucose to meet its very high energy needs. • Ketosis in dairy cattle generally occurs in the early stage of lactation in cows in negative energy balance. • Inciting factors include an inadequate post-parturient feed intake, high milk production and mobilization of body lipid to sustain energy needs, especially in cows with high body fat. • There is a lack of carbohydrate precursors such as propionate and amino acids for incorporation of fats (as acetyl CoA) into the citric acid cycle, so ketone bodies are produced at greater rates. • Ketosis is often secondary to other disorders that depress feed intake.

Saturated Fatty Acid

Lauric acid Myristic acid Palmitic acid Stearic acid

Tall Fescue Grass and Reproduction

Tall fescue grass infected with microscopic fungi called endophytes contains endophyte -produced ergot alkaloids. Pronounced impairment of reproduction occurs in livestock consuming endophyte infected tall fescue • Horses are the only livestock whose reactions to the toxic tall fescue are almost exclusively related to poor reproduction. • Mares on toxic tall fescue pasture may experience prolonged gestation, dystocia, agalactia (lack of lactation), edematous placentas and have large, weak foals with elongated hooves. • Foal survival is very low. Abortion may also occur.

Types of Bones

There are two types of bone: (i) dense cortical bone; (ii) spongy trabecular bone. • Bone consists of an organic matrix that becomes mineralized. • The organic matrix is cartilage, consisting primarily of the protein collagen. • The growth of bone in length occurs at the junction of the epiphysis and diaphysis. • As the cartilage grows, bone mineral is deposited to form bone. • When the cartilage ceases growing and is replaced by mineralized bone, the epiphysis and diaphysis unite and bone growth ceases.

Selenium Prevents Peroxidation

Vitamin E and the trace element selenium share the property of preventing peroxidation of unsaturated fatty acids in cell membranes. • Virtually all of the disorders and deficiency signs associated with these two nutrients can be explained by their antioxidant properties (an exception is the role of selenium in the thyroid gland). • Selenium helps protect against auto-oxidation of cell membranes by virtue of being a component of an enzyme, glutathione peroxidase, that reduces (by providing hydrogen) peroxides, thus converting them to innocuous products. • Glutathione peroxidase occurs mainly in the cytosol and reduces peroxides before they can attack cell membranes, whereas vitamin E acts within the membrane itself as a second line of defense. • Selenium also functions as a component of a deiodinase that converts the thyroid hormone thyroxine (T4) into its metabolically active form (triiodothyronine) by the removal of one of the four iodines in thyroxine • The usual form of selenium addition to feeds is a salt, sodium selenite. • It has a high bioavailability. The selenium in plants is largely in the form of seleno-amino acids and has a high bioavailability. • The bioavailability of selenium to ruminants is greater with high concentrate diets than with high roughage diets.

Vitamin E Roles in Reproduction

Was in the past sometimes called the 'fertility vitamin' or 'anti-sterility factor'. - This designation was an accident of history. In the early days of vitamin research, what had been called 'fat- soluble vitamin A' was fractionated into what we now know as vitamin A and vitamin D. Rats fed with these two vitamins along with all other nutrients known at that time did not reproduce normally. Supplementation of the rats with various foods restored fertility. Wheat germ oil was especially effective. • The active component was isolated and named vitamin E. • When the chemical structure was elucidated, it was named 'tocopherol' from the Greek words for childbirth and 'to bear'. • However, despite this early association with reproduction, vitamin E functions primarily as an antioxidant. • Its reproductive effects are actually due to the maintenance of tissue structural integrity by antioxidant activity

Lipids Structure 2. Lipids that containing Glycerol

• 1. Neutral Lipids: - The major neutral (uncharged) lipids in animal nutrition are the triglycerides, also known as tri-acylglycerols. Triglycerides are the fats and oils. The term triacylglycerol (TAG) is now the preferred term • 2. Phospholipids: - Phospholipids contain one or more phosphate groups. Phospholipids are important constituents of cell membranes and nerve tissue. An example is lecithin. • 3. Waxes: - The surfaces of plants are often covered in a protective layer of wax or cutin. Waxes are lipids with fatty acids esterified to an alcohol other than glycerol. • 4. Sphingolipids - Sphingolipids contain a long-chain alcohol, sphingosine. - Sphingomyelins are phospholipids containing ceramide, the fatty-acid derivative of sphingosine. - Sphingolipids are major constituents of nerve tissue (cerebrosides and gangliosides) and they occur in cell membranes in general. - common mycotoxin in maize, fumonisin, is structurally similar to sphingosine. Fumonisins inhibit sphingosine biosynthesis, causing impaired brain synthesis of sphingolipids.

Lipids Structure 3. Other Lipids

• 1. Steroids: - Are fat-soluble substances that contain the steroid nucleus. - Cholesterol is the best-known steroid, and is the ultimate precursor of many others, including vitamin D, bile acids, sex hormones (testosterone, oestrogen, progesterone), corticosteroid hormones (cortisol, corticosterone, aldosterone), anabolic steroids, etc. • Examples of steroid hormones synthesized from cholesterol. (Cholesterol -> Progesterone -> Testosterone -> Estradiol Progesterone -> Cortisol -> Cortisone Progesterone -> Aldosterone ) • 2. Eicosanoids: - Eicosanoids are compounds derived from 20-carbon and 22-carbon fatty acids, and include prostaglandins, prostacyclins, thromboxanes and leukotrienes. These substances have hormone or hormone-like roles in vasoconstriction and blood

How do specific nutrients affect immunity in dairy cattle?

• A general mechanism by which nutrients support the immune system is via provision of antioxidants. • Immune cells are characterized by high levels of reactive oxygen species (ROS) which are used, in part, to kill ingested pathogens. • In addition to high ROS generation, immune cell membranes are rich in the polyunsaturated fatty acids which are susceptible to ROS-mediated damage. • Nutrients with antioxidant properties (carotenes, vitamin E, vitamin C, zinc and selenium), therefore, support immunity

Phyto-estrogens and Reproduction

• An interesting situation is that phyto-estrogens may be involved in the regulation of reproduction of California quail. • Is reported that during dry years, stunted desert plants produced high contents of estrogenic isoflavones that inhibited quail reproduction. • Phyto-estrogens may act as 'anti-estrogens'. • A high blood concentration of Phyto-estrogens may inhibit the release of gonadotropic hormones from the pituitary and may compete with endogenous estrogens for receptor sites in target tissues such as the uterus and cervix. • Also poor reproduction of captive cheetahs in zoological parks in North America may be due in part to the effects of Phyto-estrogens in soybean meal, used in a commercial zoo feline diet. • Because, cats have a low activity of liver enzymes involved in metabolism and excretion of toxins, they may be more sensitive than livestock are to plant estrogens. • Carnivores would be expected, on an evolutionary basis, to have a lower ability to detoxify plant toxins than have herbivores, which have co-evolved with plants heavily defended with toxic chemicals. • Thus, the inclusion of plant products such as soybean meal in diets for carnivores, may have unanticipated detrimental effects.

4- Minerals

• Animals have a well-recognized appetite for salt (sodium chloride). • This salt appetite is often triggered by low contents of sodium relative to potassium in plants, as well as sodium deficiency in forages. • Sodium and potassium are two of the major blood electrolytes. A sodiumto-potassium imbalance may disturb blood electrolyte balance; therefore, the animal is attracted to sources of the deficient mineral. • Diets of herbivores tend to be high in potassium relative to sodium. • Ruminants have a pronounced ability to conserve sodium. • The rumen acts as a sodium storehouse. When sodium-deficient diets are consumed, rumen sodium is drawn upon to counteract blood sodium depletion, and potassium, which is abundant in grass, replaces sodium in saliva. • These mechanisms allow ruminants to adapt to the large sodiumdeficient areas of the world, which include most non-coastal land areas. • Northern ruminants, such as moose, eat large amounts of sodiumcontaining aquatic plants during a 3-month season and draw on the rumen sodium pool during the rest of the year.

8 - Learning and Conditioning

• Animals often exhibit neophobia, a reluctance to accept a new food. • Such a reaction can have practical implications. Where supplemental feeding of livestock is required under drought conditions, grain or pellets may be the least expensive and most convenient sources of emergency feed. • However, sheep that have never eaten these feeds may not recognize them as feed and may starve. • The learning process was accelerated if there were some experienced animals in the flock. • Animals that have learned to eat a novel feed at a young age will readily accept it again even after a several-year lack of exposure to it.

Herbivores

• At the other end of the spectrum, herbivores are animals that normally consume only plant material and have a more complex digestive tract with symbiotic microbial activity that permits the digestion of plant fiber. • Herbivores include the: - ruminants, such as cattle, - non-ruminant herbivores, such as horses and rabbits. • Ruminant animals vary considerably in their feeding strategies. • Ruminants can be classified, (special the wild ruminants) into three groups based on feeding strategy: (i) concentrate selectors; (ii) bulk and roughage eaters; (iii) intermediate feeders

Young Horse Bone Disorders

• Bone development disorders are of major concern in young horses. - This concern is particularly true in the thoroughbred racing industry. - Horses with abnormal bone development will not reach their racing potential and are susceptible to injury. • The term developmental orthopedic diseases (DOD) is used to describe a complex of bone disorders, including osteochondrosis (OCD), physitis, contracted tendons, cervical vertebral malformation (wobbler syndrome) and similar abnormalities. - OCD is a disease of the growth cartilage at articular or epiphyseal growth regions. It may occur at the growth plate (physis) or in developing the articular cartilage of joints.

Bones

• Bones serve as the structural components of the skeletal system and are also storehouses of minerals, especially calcium and phosphorus, which can be mobilized as needed. • Bone is in a continuous state of formation and mobilization - it is in a dynamic state, also known as remodeling.

Carnivores

• Carnivores, such as cats, are adapted to a meat-based diet and require a high quality, highly digestible source of nutrients. • Carnivores (mammalian, avian, reptilian) have simple digestive tracts with little microbial activity. • They may require certain nutrients, such as preformed vitamin A, some fatty acids and taurine, that in the wild can be obtained only from consumption of meat.

Carotenoids and Antioxidants

• Carotenoids are an abundant group of plant pigments; over 600 individual carotenoids are known. • They contain a long chain of conjugated double bonds, and most (e.g. beta-carotene) but not all (e.g. lycopene) have a beta-ionone ring (which is necessary for vitamin A activity). • The chain of conjugated double bonds has antioxidant activity. • In plants, carotenoids are found in the chloroplasts and function in photosynthesis. • Carotenoids are part of skin and feather pigments. They contribute to the antioxidant defenses of animals.

Carotenoids

• Carotenoids are plant pigments and antioxidants that include ß-carotene, lutein, canthaxanthin, lycopene and astaxanthin. • Carotenoids (i.e.ß-carotene) have traditionally been viewed as a source of vitamin A via the cleavage of ß-carotene precursor into active forms of vitamin A. However, carotenoids have immuno- stimulatory properties independent of their roles as precursors of vitamin A.

9 - Metabolic body size

• Common experience indicates that the feed intake of animals does not vary directly with body size. • The smallest mammal, the shrew, weighs approximately 1-6 g and eats its body weight in food daily. • It has an intense rate of metabolism and eats voraciously just to keep alive. A shrew can die of starvation after as little as 3 h without food. • It is evident that the larger an animal is, the less feed it consumes per unit of body weight. • Obviously, an elephant does not consume its body weight in feed each day.

Diabetes

• Diabetes mellitus (diabetes from Greek referring to excessive urination; mellitus from Greek referring to sugar in urine) is a metabolic disorder characterized by elevated concentrations of blood glucose (hyperglycaemia). • There are four major categories of diabetes: - (i) Type 1 (ii) Type 2 (iii) gestational (iv) secondary The major ones, Type 1 and Type 2, will be the ones discussed here. Type 2 is the most common form; 90-95% of the diabetics in the USA have this type.

3- Protein and Amino acid Concentration

• Dietary energy density has a much greater impact on voluntary feed intake than does dietary protein status. • Nevertheless, protein intake in growing animals is subject to some regulation. The growing pig, for example, has the ability to preferentially select diets adequate in essential amino acids over amino-acid-deficient diets. • Baby pigs are able to discriminate among diets varying in methionine content, and prefer a diet balanced for methionine over a methioninedeficient diet. Plasma concentrations of certain amino acids (e.g. lysine and tryptophan) provide signals for release of neurotransmitters, such as serotonin in the brain, that play a role in feed-intake regulation.

Omega-3 and 6 fatty acids

• Dietary fatty acids can affect immunity through the production of the cytokines. • A mechanism by which fatty acids affect immunity is through production of eicosanoids (e.g. prostaglandins) and leukotrienes.

Nutrition and Reproduction in Livestock

• Energy intake of beef cows is a major determinant of reproductive efficiency. • It is of particular concern in relation to estrous cycles and initiation of pregnancy. • After calving, beef cows should be rebred within 60-90 days to maintain a once-per-year calving interval. • This postpartum period is one of high energy requirements to support lactation. • If a cow is not able to consume sufficient feed to maintain a positive energy balance, initiation of estrous cycling may not occur, resulting in a prolonged calving interval. • Grazing cattle may not be able to consume a sufficient amount of forage to maintain a positive energy balance and may have a prolonged postpartum anoestrus period. • Cows with high milk production are particularly susceptible. • Feeding fat to dairy cows results in improved reproductive performance. • One mode of action is simply the provision of extra energy to prevent negative energy balance. • There is a specific advantageous effect of polyunsaturated fatty acids on dairy cow reproduction, causing changes in plasma estradiol, progesterone and prostaglandins, with stimulation of ovarian follicular growth.

Equine Metabolic Syndrome

• Equine metabolic syndrome is a disorder in horses with similarities to human metabolic syndrome. • Affected horses are obese, have insulin resistance and chronic laminitis, in the absence of usual inciting factors for laminitis. • Affected horses are often grossly obese, with excessive accumulation of adipose tissue in the crest of the neck, over the rump and around the tail head. • Treatment involves strict limitation of soluble carbohydrates in the diet. • Grain feeding and pasture should be avoided, with the diet based on good quality grass hay (1-1.5% of body weight/day). • The causes of laminitis in horses with equine metabolic syndrome are not well defined. Increased cortisol secretion caused by disturbances in fat metabolism may play a role in the predisposition to laminitis.

Foods on the Glycemic Index

• Foods with: • High glycaemic index (70-99) include corn flakes, baked potato, croissant, candy; • Medium glycaemic index (56-69) foods include whole wheat products including bread, rice, sweet potato and table sugar; • Low glycaemic index foods include most fruit and vegetables, pasta, legumes/pulses (e.g. beans and peas) and low carbohydrate foods (meat, fish, eggs, oils).

Glucose Tolerance

• Glucose tolerance is the ability of the body to regulate blood glucose after the administration of a test dose of glucose. • Glucose tolerance is impaired in both Type 1 and Type 2 diabetes. • In a normal glucose tolerance test, blood glucose returns to normal rapidly in a normal subject. • In an individual with impaired glucose tolerance, the blood glucose rises to a high peak and returns to normal more slowly, because of impaired glucose uptake by the body tissues. • In Type 1 diabetes, this is due to lack of insulin, while in Type 2 it is caused by insulin resistance. Oral Glucose Tolerance Test (OGTT)

Gossypol and Reproduction

• Gossypol is a toxin found in cottonseed and cottonseed meal. • Gossypol has some interesting effects on reproduction. - Much of the interest stems from observations on humans in China and the possible development of a male birth control pill. A Chinese scientist reported that in a 10-year period, not a single child had been born in Wang village in Jiangsu. It was discovered that a crude, homemade cottonseed oil preparation had been used for cooking in this village. Women lacked menstrual cycles and men were sterile. Subsequent investigation linked these conditions to the consumption of gossypol. • Gossypol causes males to be infertile because of non-motile sperm and depressed sperm counts. • Specific lesions occur in the spermatozoa and in the germinal epithelium. • In females, gossypol disrupts estrous cycles, pregnancy and early embryo development, particularly in non-ruminants. • The ruminant female is somewhat insensitive to the antifertility effects of gossypol.

Hypocalcaemia and parathyroid hormone (PTH)

• Hypocalcaemia is common in dairy cattle; it is referred to as milk fever or parturient paresis. • It occurs most frequently soon after lactation begins, because of a hormonal insufficiency, coupled with a high calcium demand for lactation. • Normally, bone mineral is mobilized to meet the high calcium requirement of lactation. • Mobilization of bone mineral is stimulated by various hormones, especially parathyroid hormone (PTH). • It is often considered desirable to 'prime' dry cows on a low calcium diet to stimulate endocrine activity so that when lactation begins a high rate of mobilization of bone calcium can occur as a result of increased PTH secretion. • The bone mineral is replenished during the dry (non-lactating) period.

2- Dietary Energy Level

• If feeds are sufficiently palatable to be readily consumed, the main dietary factor that controls voluntary feed intake is dietary energy concentration. • A long-standing order in animal nutrition is that animals eat to satisfy their energy requirements. • The amount of feed consumed is regulated so as to provide a constant intake of digestible energy. • If a low energy diet is used, feed intake is high, whereas with a high energy diet, feed intake is reduced. • The energy intake is about the same in each case, the lower limit of this relationship is when gut capacity is reached and the animal cannot consume enough feed to meet its energy requirements; thus its performance is reduced.

Novel Nutritional Strategies to Augment Immunity

• In addition to providing adequate amounts of all essential vitamins and minerals, other opportunities may exist for augmentation of immune function. • Provision of microbiological fractions (cell wall fractions) and probiotics (live microorganisms) in the diet have potential to support the immune system. • Although it is not fully clear how this form of nutritional supplementation benefits the immune system, it is possible it includes Toll-like receptor signaling in the gastrointestinal tract

Fat and Fatty Acid Metabolism

• In general, because lipids are insoluble in water, they are transported in blood in association with serum proteins, forming lipoproteins. • The main lipoproteins (as determined by centrifugation) are: - chylomicrons; - very low density lipoprotein (VLDL); - low density lipoprotein (LDL); and - high density lipoprotein (HDL). • Liver: • The liver has a central role in lipid transport and metabolism, with the following major functions: - It facilitates the digestion and absorption of lipids by secretion of bile. - It synthesizes and oxidizes fatty acids. - It converts fatty acids to ketone bodies. - It is involved in the synthesis and catabolism of lipoproteins.

Type 2 Diabetes

• In humans, Type 2 diabetes occurs most frequently in middle-aged and older adults. • Most people with this condition have normal or above normal concentrations of blood insulin. • Type 2 diabetes is caused by insulin resistance, which means that the body's cells cannot respond to insulin. • Insulin functions in the transfer of glucose across cell membranes. • Insulin binds to insulin receptors on the surface of tissue cell membranes, allowing glucose to enter the cells. • Insulin resistance occurs when the cell receptors do not recognize or bind insulin. • With insulin resistance, glucose uptake is impaired and hyper-glycaemia results. • Chronic hyper-glycaemia damages blood vessels and nerves, sometimes leading to blindness and limb amputation. • Some Type 2 patients respond to exogenous insulin, although insulin resistance does not imply a lack of the hormone. • In these patients, a chronic over stimulation of the pancreas to produce more insulin in response to hyper-glycaemia may eventually cause the pancreatic (beta-cells to 'wear out'). • Besides its role in diabetes, insulin resistance is also a major factor in the development of metabolic syndrome, in both humans and equines.

Serum Calcium

• In most species, calcium absorption is regulated by need, via the 1,25-OHD3 (vitamin D) pathway, ultimately controlled by the serum calcium concentration. • Serum calcium is homeostatically regulated by the actions of PTH (in response to hypocalcemia) and calcitonin (in response to hypercalcemia). • Calcitonin is produced in the thyroid gland. • Excess dietary calcium is not absorbed in most species and is excreted in the feces. • Urinary excretion is not a major pathway of calcium loss in most species.

Non-Ruminant Nutrition and Immunology

• In non-ruminants: affect one or more indexes of immunity • essential amino acids, • linoleic acid, • vitamin A, • folic acid, • vitamin B6 , • vitamin B12, • vitamin C, • vitamin E, • zinc, • copper, • Iron, • selenium. • Also, potential roles of magnesium in support of the immune system. Vitamin E and zinc have received the most attention as immuno-stimulatory nutrients.

5 - Forage Composition

• In ruminants, forage quality and composition influence feed intake. • A major factor regulating forage intake is the neutral detergent fiber (NDF) and its digestibility. • The NDF seems to be the major component limiting rumen fill. In the rumen, only when the NDF is digested is its effect on rumen fill eliminated ,confirmed this relationship with cattle; the intake of forage is regulated by the intake of indigestible NDF. • The water-holding capacity of feedstuffs may affect feed intake. Feeds with high water-holding capacity include wheat bran, beet pulp, and grains (e.g. wheat.

Caloric Restriction and Longevity

• In the 1930s, McCay et al. (1935) at Cornell University reported that growing rats fed a severely restricted allotment of food, sufficient to cause growth to cease, had elongated lifespans. • When they were older than the normal lifespan of rats, they were still capable of growing and nearly reaching normal body size. This study was the first major research which demonstrated that caloric restriction retards ageing and extends median and maximal lifespan. • Since this work, similar findings have been reported for a variety of species including rats, mice, fish, flies, worms and yeast. • A 25% diet restriction of dogs resulted in increased lifespan in a two-decade study (Lawler et al., 2008). • Large animals tend to live longer than small animals, a relationship which correlates with metabolic rate. • The naked (African) mole rat has an extraordinarily long maximum lifespan exceeding 28 years. Mole rats in captivity live over nine times as long as similar sized mice. They show no decline in fertility even into the third decade of life, and have never been observed to develop neoplasms. • Compared to other animals of similar size, such as sheep and pigs, humans also have an extremely long lifespan.

Vitamin A

• In the feed is more common as pigments (Carotenoids) provitamin A; • Storage most in the liver • Horses, Cattle, and Chickens can absorb more carotenoids than swine, sheep and rats; • Cats can not convert carotenoids in Vitamin A. • Functions: - Vision - Gene transcription, - Immune function, - Embryonic development and reproduction, - Bone metabolism, - Haematopoiesis, - Skin and cellular health, - Teeth, - Mucous Membrane.

Lipids Structure

• Lipids are defined as those constituents of plants and animals tissue that are soluble in organic solvents like diethyl ether. • The lipids content of feeds is usually referred to as the ether extract (EE). Dietary lipids of importance in animal nutrition are mainly fat and oils, which are energy-rich compared with carbohydrates, having about 225% the energy content to carbohydrates on an equal weight basis. They also function as components of cell membranes and as the 'insulation' of nerves. The lipid component of animal products (body fat, cholesterol) is important in human nutrition, and is implicated in various human health pathologies

Lipid Digestion - Auto-Enzymatic Animals

• Lipids are hydrophobic, meaning that they are not soluble in water. • Therefore, a fundamental aspect of lipid digestion is to 'dissolve' fat in water, that is, in the aqueous medium of the digestive tract. • This is accomplished by emulsification, or the dispersal of lipid in water in the form of very small droplets • Bile contains bile salts, lecithin, and substances derived from cholesterol so it acts as an emulsifier. • It attracts and holds on to fat while it is simultaneously attracted to and held on to by water. • Emulsification increases the surface area of lipids over a thousandfold, making them more accessible to the digestive enzymes. • Once the stomach contents have been emulsified, fat-breaking enzymes work on the triacylglycerols and diglycerides to sever fatty acids from their glycerol foundations. • As pancreatic lipase enters the small intestine, it breaks down the fats into free fatty acids and monoglycerides. • Bile salts envelop the fatty acids and monoglycerides to form micelles. • Micelles have a fatty acid core with a watersoluble exterior. • This allows efficient transportation to the intestinal microvillus.

10 - Other factors

• Many other factors, often in combination with some of the items mentioned before, may influence feed intake. • Smell is very important. Sometimes animals will reject a diet or a forage without even tasting it, suggesting that olfactory cues are involved. • Grazing animals will not graze in the immediate area of manure droppings, but the grass around the dung is cut and taken. • Fatigue can limit feed intake. Ruminants consuming coarse forages may become fatigued in seeking, ingesting, chewing and ruminating feed. • Rumination time is directly related to plant cell wall content. Sheep and cattle have a maximum rumination time of approximately 10h/day and cannot be forced to ruminate beyond this limit. • Illness (sickness behaviour) that involves activation of the immune system results in loss of appetite. This is a consequence of the metabolic actions of various cytokines, such as interleukins and tumour necrosis factor.

Metabolic Syndrome

• Metabolic syndrome has been proposed as a disorder in humans characterized by: - impaired insulin sensitivity, - hyper-glycaemia, - elevated blood triacylglycerol (TAG), - abdominal obesity and hypertension. Insulin resistance refers to the lack of effect of insulin in stimulating glucose uptake by tissue cells, resulting in hyper-insulinaemia and hyperglycaemia. Similarly, normal effects of insulin on lipid metabolism are reduced, causing elevated blood TAG and lower HDL cholesterol concentrations. • Metabolic syndrome increases risk of Type 2 diabetes and cardiovascular disease. • Dietary factors may influence hyper-insulinaemia. • For example, chili peppers (Capsicum annum) decrease postprandial (after eating) blood insulin concentrations, which may have a favorable effect on lowering insulin, obesity and cardiovascular disease. • A number of other herbs can have similar effects.

Mycotoxins

• Mycotoxins play a role in other leg disorders of poultry. • A frequent cause of rickets in young poultry is calcium deficiency induced by aflatoxins. - Aflatoxins cause liver damage and reduced bile secretion. - Bile is necessary for the absorption of fat-soluble vitamins such as vitamin D. - Aflatoxin reduces vitamin D absorption and the liver damage impairs formation of 1-25-OHD3 in the liver. - Another mycotoxin, fusaro-chromanone, has been implicated as a causative agent of TD in broilers.

Nutrition and Immunology

• Nutrition has an impact on every physiological process in the body. • Hence, it should not be surprising that nutrition also has important implications on immunity and incidence of disease. • While scientists have known for many years that nutrition influences immunity, only in recent years have specific mechanisms by which nutrients affect immunity become apparent.

Nutrition and Reproduction

• Nutrition plays important roles in reproductive success. • Growth of the fetus and placental tissues have a high priority for nutrients, especially those relating to energy and protein requirements. • The ultimate role of all organisms is the successful completion of reproduction.

Energy Metabolism and Reproduction

• On an evolutionary basis, animals developed physiological mechanisms which inform them metabolically as to whether undertaking reproduction at a particular time is wise. • For example, it would not be an evolutionarily sound strategy for wild ungulates in northern regions, to give birth in midwinter. • A developing dry season, would result in reduced feed availability, and thus reduced availability of energy-providing nutrients. • Reduced energy intake could provide a cue to alter hormonal status to inhibit reproduction. • In general, low energy intakes and poor body condition will tend to impair reproduction. • Nutrients that are involved in energy metabolism, such as enzyme cofactors, will if deficient impair reproduction. • For example, phosphorus has a role in phosphorylation of sugars in carbohydrate metabolism. • Dietary phosphorus deficiency thus provides a cue that energy metabolism is impaired. • Phosphorus deficiency of livestock is relatively common in various parts of the world where soil contents of the mineral are low.

Vitamin E as an Antioxidant

• Only metabolic function of vitamin E is as a cellular antioxidant, responsible for stabilizing cell membranes. • All symptoms of vitamin E deficiency are in fact manifestations of peroxidation of cell membranes. • Vitamin E associates with lipid micelles in the intestine, and is absorbed coincidently with fat absorption. • It is transported in the blood in association with lipoproteins and within cells is associated with tocopherol-binding proteins.

1- Palatability and Feed Preference

• Palatability is a determinant of feed intake. • Palatability is the summation of the taste, olfactory and textural characteristics of a feedstuff that determine its degree of acceptance. • Taste is a major component of the palatability complex. • The major taste responses are sweet, salty, bitter and acid. • A fifth taste sensation has been recognized, called umami (Japanese meaning savory deliciousness). The umami taste is considered to represent the taste for dietary protein • Virtually all animals except strict carnivores show a preference for the sweet taste (sweet tooth). The sweet taste is recognized by a taste bud receptor composed of the products of two genes. • In the domestic cat and others such as the tiger and cheetah, one of the genes is not functional and is not expressed . • Most animals also show a pronounced appetite for salt. This is particularly true of herbivores. • The attraction for sweet taste (sugars) and fat is of obvious evolutionary benefit, attracting animals to feeds that are rich in energy. While a 'sweet tooth' was of obvious benefit to pre-modern humans, it has become a liability today. • Other palatability factors for various species include size, shape, smell, color and movement.

Fatty Acid Metabolism

• Pathways of fatty acid metabolism involve fatty acid biosynthesis, oxidation, and metabolism of essential fatty acids. • These processes, especially fatty acid biosynthesis and degradation, are intertwined with pathways of carbohydrate metabolism because of the central roles of acetyl CoA in both fat and carbohydrate metabolism. • Fatty acid oxidation • Fatty acids are oxidized in the mitochondria by being converted to acetyl CoA, which is then catabolized in the citric acid (or TCA) cycle reactions. Fatty acids react with coenzyme A (CoA) intracellularly to produce activated fatty acids (acyl CoA). This step requires ATP. • The activated fatty acids are transported across the mitochondrial membrane in association with carnitine. • Fatty acid synthesis • Fatty acid synthesis, like (b-oxidation, involves metabolism of two carbons at a time, in the form of acetyl CoA. • However, fatty acid synthesis is not simply the reversal of B-oxidation, but involves different enzymes located at a different intracellular site. • This separation allows each process to be individually regulated and integrated according to metabolic needs. B-Oxidation occurs in the mitochondria, whereas fatty acid biosynthesis occurs in the cytosol.

Peroxidation

• Peroxidation (auto-oxidation) of lipids exposed to oxygen is an important factor in the deterioration (rancidity) of fat-containing feeds and also for damage to tissues in vivo, where it may be important as a cause of cancer, inflammatory diseases, atherosclerosis and ageing. • The deleterious effects of lipid peroxidation are caused by free radicals produced during peroxide formation from polyunsaturated fatty acids. • A chain reaction occurs, in which the peroxidation processes generate free radicals which initiate further peroxidation. • Other sources of free radicals and lipid oxidants (reactive oxygen species; ROS) are the superoxide free radical anion and hydrogen peroxide. • The superoxide ion is a by-product of normal metabolism. Free radicals have an unpaired electron and are very electrophilic (i.e. they react to gain another electron). • Superoxide is detoxified by the enzyme superoxide dismutase, producing hydrogen peroxide. • Hydrogen peroxide is also a potent oxidant, and is detoxified by the reaction with reduced glutathione (GSH) catalysed by glutathione peroxidase and with catalase • Lipid peroxidation is prevented by antioxidants. • A number of antioxidants are used as preservatives to prevent auto-oxidation of lipids in foods and feeds. • These include butylated hyroxyanisole (BHA), butylated hydroxytoluene (BHT) and ethoxyquin. • Naturally occurring antioxidants include vitamin E and vitamin C. • Selenium has antioxidant activity by way of its role in glutathione peroxidase. • Polyphenols from plant sources also have antioxidant activity. • The phenolic group(s) of antioxidants is the active site; most antioxidants are phenolics, including vitamin E. • Antioxidants either reduce the rate of initiation or interfere with chain propagation. • Those that reduce initiation include catalase and other peroxidases that react with hydroperoxides, and chelators of metal ions (e.g. ethylenediaminetetraacetic acid, EDTA). • Principal chain-breaking antioxidants include superoxide dismutase, which traps superoxide free radicals, and vitamin E, which traps peroxide free • The tocopheroxyl free radical product is reduced back to tocopherol by ascorbic acid (vitamin C). • The ascorbate free radical is converted to ascorbate and dehydroascorbate, which are not free radicals. • Unsaturated fatty acids are susceptible to peroxidation, because they have double bonds which react with oxygen. • The more double bonds (i.e. the more unsaturated), the greater the susceptibility to auto-oxidation.

Ratites

• Ratites (ostriches, emu and other large flightless birds) are susceptible to leg weakness problems. • When fed high energy diets, young ratites may have excessive weight gain that causes great stress on the legs, which may become bowed or misshapen. Therefore, young ratites should be raised on pasture if possible, with limited exposure to concentrate feeds.

Chromium

• Several studies have indicated that supplementation of chromium to dairy cattle, in a biologically available form (e.g. chromium-amino acid complex or chromium-yeast), benefits immunity. - Help the increased blastogenesis in lymphocytes recovered from sick calves. - Chromium increased development of titre to ovalbumin immunization and was reported increased titre in chromium-supplemented cows following immunization with infectious bovine rhinotracheitis virus (IBRV) antigen (but not parainfluenza virus Type 3).

Zinc

• Specific roles that zinc plays in support of immunity are plentiful, well established and too numerous to reports. • However, it should not be surprising that zinc plays an essential role as an 'immunonutrient' as it is associated with over 300 proteins . • Clearly, a zinc deficiency has opportunity to impact a large number of cellular events which might compromise immunity .

Synthetic Antioxidants (Preservatives)

• Synthetic antioxidants include: - Ethoxyquin (Santoquin®), - BHT; - BHA. • They are phenolic compounds, and are very effective at preventing oxidation (rancidity) of stored feeds and are commonly used for this purpose. (Ethoxyquin is not actually a phenolic).

Sucrose, Fructose and Metabolic Syndrome

• Table sugar (sucrose) is widely added to processed foods. • The availability of abundant amounts of sucrose is a recent development. • Before the discovery of the Americas and the development of largescale sugarcane production, most humans consumed virtually no sugar, and very small amounts of honey. • Beginning in the 1970s, high fructose corn syrup (HFCS) has become an extensively used sweetener. • Beginning in the 1970s, high fructose corn syrup (HFCS) has become an extensively used sweetener. • The rapid increase in sucrose and HFCS consumption by humans has been paralleled by a rapid increase in 'diseases of Western civilization' such as: - diabetes, - coronary heart disease, - obesity, - hypertension, - kidney disease - metabolic syndrome, Suggesting a possible relationship between sugar consumption and these diseases.

6 - Environmental temperature

• The environmental temperature has an important influence on feed intake. • The metabolic rate of an animal is at a minimum in the comfort zone, also known as the zone of thermoneutrality. • As environmental temperatures decrease below the comfort zone, an increase in metabolic rate is necessary to maintain body temperature. • Thus feed intake increases as environmental temperature decreases. • It is difficult to quantify these relationships (e.g. to indicate that with a 10°C decrease in environmental temperature the feed intake will increase by a certain percentage) because of the involvement of other factors, such as humidity and wind velocity • Hormonal changes influence winter feed intake. • During a period of exposure to cold, the comfort zone is lowered by alterations in the output of such hormones as thyroxine. • The winter hair coat also provides insulation to reduce energy requirements. • Wild ungulates, such as deer, accumulate large amounts of body fat in the summer and have a very low feed intake in the winter, surviving on body-fat stores. • Domestic ruminants appear to have vestiges of this photoperiod-controlled feed intake pattern.

General Concepts of Immunology

• The immune system can be generally separated into three broad components: • (i) natural immunity; • (ii) innate immunity; • (iii) acquired immunity. - All of these must be fully developed and functioning properly to provide adequate immunological protection. - Natural and innate immunity are typically grouped together under the category of innate immunity.

Innate Immunity

• The innate immune system is an evolutionarily ancient mechanism to fight disease and represents the antigen-non-specific defense mechanisms of the immune system that is elicited immediately or within several hours (0-4 h) after exposure to an antigen. • It consists of several anatomic, physiologic and cellular components. • Anatomic aspects include the epithelial barriers to infection provided by the skin, lung, mammary and gastrointestinal tract. • Secretion of hydrochloric acid and digestive enzymes by the gastrointestinal tract also aids in preventing entry of pathogens into the body. • Complement is also considered a component of innate immunity. • But, in addition to these, animals possess a cellular component of innate immunity. • The cellular component consists of phagocytic cells (e.g. neutrophils and macrophages) that are activated at sites of infection and then attack and kill pathogens before pathogens have the opportunity to proliferate and cause a significant infection. • Innate immunity is a non-selective immune system. • It does not modify itself depending upon the type of pathogen challenge. • Instead, it prevents infection by targeting general properties of pathogens. For example, few pathogens can withstand the low pH of the stomach (abomasum) and most should be digested by the digestive enzymes of the gastrointestinal tract. In fact, the majority of organisms encountered by an animal on a daily basis do not cause disease under normal circumstances as they are readily detected and eliminated by the innate immune system.

Immune system and vitamin D

• The most recent essential nutrient with reported benefit to the immune system is vitamin D. • Was reported a link between receptors and vitamin D-mediated innate immunity and suggested that differences in ability of human populations to produce vitamin D may contribute to susceptibility to microbial infection.

Lipid Digestion - Alloenzymatic Animals

• The natural diets of ruminants tend to have a low concentration of lipids. • Leaf lipids are mainly galactolipids and phospholipids, and miscellaneous substances such as waxes, plant pigments (chlorophyll, carotenoids) and essential oils. • Seed lipids are primarily triglycerides (TAGs); therefore, modern feedlot and dairy diets based on grains have a preponderance of dietary lipid as TAGs. • Rumen microbes utilize lipids inefficiently. • In non-ruminants, fats are emulsified by bile before digestion in the small intestine. • In the rumen, there is a lack of emulsifying agent, pancreatic lipase, in the rumen, so high (above 5%) amounts of dietary fat can cause reductions in fiber digestibility by a physical coating action on feed particles. • Fats also have an inhibitory effect on rumen microbes; unsaturated fatty acids are toxic to rumen bacteria. • Fatty acids are neutralized at the rumen pH and converted to soaps, which are salts of fatty acids. • Potassium soaps are readily absorbed in the small intestine, whereas calcium soaps have lower absorbability. • Ruminants secrete a high proportion of taurine-conjugated bile acids, which facilitates solubilization of fatty acids in the acidic duodenum of ruminants. • In ruminants, the majority of lipid entering the small intestine is in the form of FFAs (80-90%) in contrast to non-ruminants, in which most lipid is in the esterified form. • One of the microbial transformations of lipids in the rumen is the synthesis of odd and branched chain fatty acids, which aid in maintaining optimal fluidity of microbial cell membranes. • The main fatty acid in mixed rumen bacteria is stearic acid, whereas palmitic acid is predominant in protozoa. • Protozoa contain a greater proportion of unsaturated fatty acids and CLA than do bacteria.

Lipids Structure 1. Fatty Acids

• The properties of a particular fat or oil are determined by the fatty acids they contain. • Fatty acids differ in the number of carbons atoms and in the amount of hydrogen they contain. • Those which are fully saturated with hydrogen are called saturated fatty acids, while the insaturated fatty acids contain one or more carbon-carbon double bonds that are not saturated with hydrogen. • Fatty acids contain a carboxyl group (-COOH) at the of carbon chain. • Fat contain mainly saturated fatty acids and are solids at room temperature. • Oils that contains insaturated fatty acids are liquids at room temperature. • The short-chain fatty acids (SCFA), such as acetic, propionic and butyric acids, are the VFA of rumen fermentation and are not generally viewed as lipids, as they are water soluble. • Unsaturated fatty acids may be either monounsaturated fatty acids (MUFA) or polyunsaturated fatty acids (PUFA). MUFA have one double bond, while PUFA have two or more double bonds.

Factors Affecting Feed Intake

• The regulation of feed intake and appetite is a complex subject. • Maximal feed intake can be achieved only with free choice and water available. When water is restricted, feed intake is reduced. • If a group or pen of animals goes off feed, the first thing to check is the water supply. • Large amounts of water are required to moisten food in the gut, especially in herbivores. • Ingredients with high water-absorbing properties, such as bran, increase the water requirements. 1- Palatability and Feed Preference 2- Dietary Energy Level 3- Protein and Amino Acid Concentration 4- Minerals 5- Forage Composition 6- Environmental Temperature 7- Pregnancy and Lactation 8- Learning and Conditioning 9- Metabolic Body Size 10- Other Factors.

Calcium and Phosphorus

• The requirements and metabolism of calcium, phosphorus and vitamin D are closely interrelated. • Bone mineral consists mainly of tricalcium phosphate and other salts of these two minerals. • Approximately 99% of the calcium and 80% of the phosphorus in the animal body occur in the bones and teeth. • Phosphorus is very important in cellular metabolism. • Many of the intermediates of carbohydrate metabolism are phosphorylated (e.g. glucose-6- phosphate, fructose-1,6-diphosphate and phosphoglyceric acid). • The central compound in energy metabolism, adenosine triphosphate (ATP), is a phosphorylated compound. • DNA and RNA contain phosphorylated pentose sugars. • Thus, reactions involving phosphorus are crucial to animal metabolism. • A number of critical metabolic enzymes are regulated by calcium and/or phosphorylation, including: - glycogen synthase, - pyruvate kinase, - pyruvate carboxylase, - glycerol-3-phosphate dehydrogenase, - pyruvate dehydrogenase. • Calcium and/or phosphorus deficiency symptoms reflect the metabolic functions of these nutrients as well as vitamin D. • Vitamin D is functional in calcium and phosphorus absorption, and in bone mineralization.

Acquired (adaptive) immunity

• The second arm of the immune system is termed the 'adaptive system' and is characterized by the production of antibodies which are directed against specific antigens. • The use of vaccines to protect animals from various pathogens is an example of acquired immunity. • Acquired immunity can be classified as either: - Cell-mediated; - Humoral immunity. • Cell-mediated immunity represents the immunological response associated with immune cells which act directly against pathogeninfected cells. • Humoral immunity on the other hand involves the generation of specific antibodies that are directed against the invading pathogens.

The Thyroid Hormones - Major Integrators of Metabolism

• The thyroid gland produces several thyroid hormones (THs) that have many important roles in virtually all aspects of animal metabolism. • The major THs are thyroxine (T4), also referred to as tetraiodothyronine, and triiodothyronine (T3). • T4 is synthesized in the thyroid gland, and released into the circulation. T4 is converted into the metabolically active form, T3, in the tissues. • Numerous plants contain thyroid inhibitors, or goitrogens. • Plants in the cabbage family (genus Brassica) are particularly noteworthy for their goitrogenic activity. • Brassicas contain sulfur-containing compounds called glucosinolates. Derivatives of glucosinolates, such as thiocyanates and isothiocyanates, are goitrogens. • These compounds inhibit the uptake of iodine by the thyroid. The shortage of iodine in the gland impairs production of THs, causing the thyroid gland to enlarge (goitre). Causes of goitre include either a dietary deficiency of iodine, presence of goitrogens or a combination of both.

Polyphenolic Antioxidants

• There is a great deal of interest in polyphenolics in fruits and vegetables. • They are believed to have beneficial effects on human health by functioning as tissue antioxidants. • Phenolic compounds contain aromatic rings with hydroxyl groups. • Polyphenolics have more than one hydroxyl group. • These phenolic groups function as antioxidants by providing hydrogen to reduce oxidants (Note that this is how vitamin E functions). • An example of a phenolic antioxidant is resveratrol

β-carotene Roles in Reproduction

• There is evidence that β-carotene may play a role in reproduction. • The corpus luteum of cows contains high concentrations of β-carotene, an observation which has stimulated research on its effects on dairy cow reproduction.

Type 1 Diabetes

• This type occurs most often in childhood, and was formerly called juvenile-onset diabetes or insulin - dependent diabetes mellitus. • Type 1 diabetes is an autoimmune disorder; the immune system produces antibodies that attack and destroy the insulin-producing (beta-cells of the pancreas. • Loss of (beta-cells results in a lack of insulin production), leading to the onset of the signs of diabetes. • These signs include extreme: - thirst, - hunger, - frequent urination - fatigue. • These symptoms are all a result of elevated blood glucose.

Vitamin D Function and Deficiency

• Two forms of Vitamin D: - Ergocalciferol (D2, in plants tissue) - Cholecalciferol (D3, in animal tissues) Function: - The major biologic function of vitamin D is to maintain normal blood levels of calcium and phosphorus - Vitamin D aids in the absorption of calcium, helping to form and maintain strong bones - it promotes bone mineralization in concert with a number of other vitamins, minerals, and hormones - it maintains normal cellular growth and function - it maintains healthy immune function and preventing excessive inflammation - it inhibits parathyroid hormone secretion from the parathyroid gland • Deficiency: - Birds: rickets, eggs with bad shells - Mammals: rickets, enlargement of metacarpal and metatarsal bones, and other deformities in bones.

Osteoblasts and Osteoclasts

• Two types of cells, osteoblasts and osteoclasts, are important in the remodeling process. Osteoblasts - function in bone formation Osteoclasts - responsible for bone mobilization

Vitamin A Roles in Reproduction

• Vitamin A is essential for reproductive function in both males and females, and for fetal development. • Vitamin A deficiency results in weak, dead or malformed offspring. • There is evidence that vitamin A functions in steroidogenesis (synthesis of steroid hormones) such as progesterone. • Vitamin A may also have a direct effect on the uterine environment, including formation of normal uterine epithelial tissue. • Vitamin A also affects embryo development by regulating cell differentiation and proliferation. • In the male, vitamin A is required for spermatogenesis. • Hypervitaminosis A can also cause reproductive problems, including abortion, fetal resorption, birth defects and low neonatal viability.

Vitamin C as an Antioxidant

• Vitamin C, or ascorbic acid, functions as an antioxidant, in addition to its role in vitamin E recycling. • Its synthesis involves formation of L-gulonolactone from glucose, which is converted to ascorbic acid by the enzyme L-gulonolactone oxidase. • Most animals have this enzyme. A few, including humans, other primates, guinea pigs, fruit-eating bats, some fruit-eating birds and some fish lack this enzyme and so have a dietary requirement for vitamin C. • Besides its role as an antioxidant, ascorbic acid is also required in collagen synthesis.

Vitamin D

• Vitamin D is aptly known as 'the sunshine vitamin'. • It is formed by the irradiation of sterols in plants and in the skin of animals. Vitamin D occurs in two major forms: - (i) vitamin D2 (ergo- calciferol); - (ii) vitamin D3 (cholecalciferol). - Ergocalciferol is activated plant sterol; - Cholecalciferol is activated animal sterol. • Animals kept in total confinement, as is the case in modern pig and poultry facilities, are not exposed to sunlight and will require a dietary source of vitamin D. • Grazing animals exposed to sunlight normally do not require supplementation with vitamin D. • In the winter in northern climates, the amount and intensity of sunlight is often too low for adequate synthesis of vitamin D in the skin, and provision of a supplement is recommended. • In all animals, vitamin D2 is converted to D3 , with D3 being the metabolically active form. The efficiency of conversion is very low in poultry. • Although commonly classified as a vitamin, vitamin D actually functions as a steroid hormone. • It meets the criteria for a hormone. • The hormonal form is the hydroxylated compound, 1,25- dihydroxyvitaminD3 . • It is produced in a gland (the kidney) and is transported by the blood to the target tissue (the intestine). • Its formation and secretion are controlled by a feedback mechanism (blood calcium concentration). • The major physiological role of vitamin D is to regulate the absorption of calcium from the intestine, by regulating the mucosal synthesis of calcium-binding protein (calbindin). • There are some interesting differences among species in vitamin D regulation of calcium absorption, reflecting evolutionary background. - For example, llamas have a high dietary vitamin D requirement because in their native habitat at high elevations in the Andes, they are exposed to intense solar radiation.

Vitamin E and selenium

• Vitamin E and selenium play overlapping and essential roles in support of the immune system in ruminant animals. • A large portion of the benefits of these nutrients is related to their functions as antioxidants. • Feeding supplementary selenium to ruminant animals reduces incidence of diseases (including intra-mammary infections) and several studies have identified potential mechanisms

Vitamin E

• Vitamin E is a group of eight fat soluble compounds that include four tocopherols and four tocotrienols. • Vitamin E deficiency, which is rare and usually due to an underlying problem with digesting dietary fat rather than from a diet low in vitamin E. • Deficiency: • Birds: encephalomalacia, exudative diatheses (severe edema of the subcutaneous tissues), muscular dystrophy. • Swine: Exudative diatheses, Muscular degeneration, liver necrosis. • Bovines: Fetal reabsorption, Metritis, testicular degeneration.

7 - Pregnancy and Lactation

• Voluntary feed intake shows characteristic changes in pregnancy and lactation. • In late gestation, feed intake decreases, perhaps an effect of the high levels of circulating estrogens at that time that may alter metabolism to reduce energy requirements. • During peak lactation, feed intake is very high, to support high levels of milk production. • In dairy cattle, the peak in feed intake is reached after peak lactation occurs, so body reserves are mobilized during this period.

Energy usage and immune responses

• While activation of physiological processes within the animal in response to an immunological challenge is necessary for survival, there is an associated energy cost which reduces the overall productivity potential. • Indeed, creating and maintaining a febrile response alone is very energy intensive. • It has been estimated that there is approximately a 10-15% increase in energy usage for every degree of body temperature increase associated with an immune response.