Animal Nutrition True/False
True
Chickens are very efficient in grinding feedstuffs because of "koilin rods" that protrude from the surface of the luminal lining of the gizzard! Those rods are made of, essentially, the protein-carbohydrate complex known as, as you guessed it, "koilin!"
False
Two long ceca are the primary fermentation sites for chickens, but each entrance is narrow and also protected by mucosal folds with villi projecting toward the lumen center. That is the reason that VFA produced in the ceca account for only 30% of the total energy needs
True
Uric acid is usually associated with poultry because they do excrete the N end product as uric acid, which can be synthesized from Gln, Gly, and Asp. However, the breakdown of purines can also generate uric acid. That's why mammals' urine also have a small amount of uric acid
False
Using a "radioactive indicator is a good approach to study mineral metabolism because we are not really increasing the dietary content or physiological concentration of the mineral in question, and furthermore, we can easily determine its concentration
False
Using a simpler formula, "Na + K - Cl" to determine the dietary electrolyte balance is not appropriate because we have to also account for the effect of Ca, Mg, P, and S, which are, obviously, important part of electrolytes in body water
True
"Eyes in the front? The animal hunts. Eyes on the side? The animal hides." Perhaps, those are true because forward facing eyes allow an animal to see and judge depth, which is needed to track and pursue a prey. On the other hand, eyes on the side allow for greater peripheral or side vision, which is important for the protection... especially, when grazing or feeding
True
"Prebiotic" is a fibrous substance that can stimulate the growth of, eg lactobacillus, bifidobacterium, and other beneficial bacteria. Some examples of prebiotics are fructoplogosaccharides, inulin, and mannanoligosaccharides" and the production of short chain FA from those carbs may be responsible for their beneficial effects
True
"Total dissolved solids (TDS)" can be used to assess the usefulness of H2O as drinking water, and TDS should be less than 3000 and 5000/7000 ppm for poultry and pigs/many others, respectively. Obviously, we should try to provide cleaner drinking water as possible because there is some indication that those guidelines may not be appropriate in some situations
False
As we mentioned, we should not say "non-essential" amino acids because, metabolically, all amino acids are essential! Similarly, we should not say "non-essential minerals" for the very same reason
True
A rapid release of soluble protein can lead to the formation of froth, which can block cardia; thus, gases cannot escape, which can lead to "bloat"! On the other hand, a rapid fermentation can increase lactic acid tremendously and reduce pH, which can destroy some papillae and lead to dehydration/circulatory collapse
False
A typical corn-soy diet contains sufficient goitrogens to increase the size of thyroid 5 to 6 fold. Fortunately, the use of iodized salt and dicalcium phosphate can provide 0.30 ppm I, which can satisfy the need for pigs and chickens... thus, no need for supplementation
True
Although most carbohydrates would be fermented by rumen microbes, a small amount of carbohydrates can escape microbial fermentation. Unfortunately, those escaped carbohydrates cannot be digested and absorbed efficiently by the host animal's digestive enzymes
True
Although there have been some controversies, the pigs "saliva" probably contains a low concentration of amylase or ptyalin. On the other hand, the saliva of chickens, horses, ruminant species, dogs, or cats does not contain any enzyme... not at all
False
Although we can estimate the maintenance "protein" need by using fasting metabolism, it is not enough simply because we need additional protein for, eg, heat increment when consuming some protein, protein to support normal activity, etc
True
Apolipoprotein B is essential for the formation of chylomicron, which can transport dietary lipids from the intestine to other locations. It is also involved in the formation of other carrier proteins such as LDL, HDL, and VLDL, all of which you're familiar with or have heard about!
False
As we may have mentioned, we could train pigs to press a switch to get a sucrose solution, indicating that pigs do have taste "preference". A sense of taste in chickens is, however, associated more with aversion, even though they have a substantial number of taste buds
True
As we mentioned, there are extensive conversions among FA within a particular group. Thus, often, we just don't know which FA is doing what! That's the reason, instead of using a specific FA name, we usually use the term, eg w-3, w-6, or w-9 FA
False
As we mentioned, unlike microbes, humans cannot really synthesize many "vitamins". However, we can still synthesize some vitamins such as vitamin D from cholesterol, niacin from tryptophan, vitamin C from glucose... and some others
True
Because of some fundamental relationship between salt and water, a high salt intake may lead to hypertension in some individuals. A very strict salt restriction can reduce blood pressure by 7 to 8 mm Hg in those folks, however, that may not help those individuals
True
Body fat of ruminant species tends to be more saturated because rumen microbes can hydrogenate or saturate 60 to 90% of unsaturated FA, which can be incorporated directly into the host's body tissues and organs
False
Chickens excrete excess N in a nearly solid form, and they can also produce a lot of metabolic water. Thus, chickens can tolerate a temporary water deprivation. By the way, metabolism of lipids can yield 50% of its weight as metabolic water, which is important for chickens!
True
Chickens may be able to utilize some "non-protein nitrogen" such as urea, because, unlike pigs, their ceca and colon seem to be capable of absorbing some amino acids
False
Compared with long-chain FA, some "short and medium chain triglycerides or MCT" can be utilize well by, eg young pigs simply because those FA can be absorbed directly into the portal circulation by forming micelles very easily
True
During normal metabolic processes, we can generate a lot of acids, such as CO2, lactic acid, keto acids, H+, and sulfate, and that's the reason, nutritionists started paying attention to the "electrolyte balance" about 30 years ago. Clearly, excess acids must be neutralized, period!
False
Fiber may have beneficial effects on diarrhea and constipation, the two seemingly opposite conditions! Why or how? Well, among others, the water holding capacity of lectin may be mostly responsible for the fiber's positive effects!
True
For lipase to be active for digestion of lipids/triglycerides, it seems that we also need bile and colipase! Without bile and colipase, lipase would be denatured and lipase cannot attach to lipid droplets without co-lipase
True
For the "protein synthesis or translation", we just have to have all 20 amino acids in the adequate amount simultaneously! in addition, we should remember that there would be many mistakes in the process, which can greatly increase the energy expenditure!
False
Having the reticular groove is very important for young ruminants because milk can flow directly into the abomasum. Milk proteins can be coagulated by rennin to form a curd or Ca caseinate, which increases the passage rate, thus, increasing the efficiency of utilization
False
Hemicellulose is a complex, heterogeneous mixture of different polymers of monosaccharides found in cell walls, and it is utilized by animals more easily than cellulose because of less H-bonding and less tightly bound structures, even though it has more sugar units than cellulose
True
If we feed more "digestible carbohydrates" to eg nonruminant species such as pigs, we'll likely see more fermentation in the stomach and less in the hindguts. As would be expected, the primary VFA would still be acetate... rather than butyrate and propionate though
False
In most species, all FA can be absorbed through the lymphatic system via chylomicron. In the chicken, however, long chain FA, as well as short and medium chain FA, are absorbed directly into the portal circulation through, eg VLDL
True
In practice, fattening or finishing is an integral part of growing animals for, eg, commercial beef production. However, strictly speaking, it is not part of the "growth" because growth is the increase in "protein, minerals, and water"!
False
It is important to realize, unlike "dispensable" nutrients, "indispensable" nutrients cannot be synthesized within the body. Thus, those nutrients would have to be provided in the diet.
True
It is mostly associated with the maintenance in humans or mature animals, but in terms of nutrition, the liver is very important for one obvious reason! that is, essentially, all the absorbed nutrients would go through the liver, and then possibly be modified!
False
It is possible that more than 50% of public wells in the United States may have a greater concentration of nitrite in water than the EPA standard. Fortunately, we don't usually have to worry about that unless microbes in water can convert that to nitrate, which can reduce the oxygen carrying capacity
True
It seems that chickens have a poorly developed "sense of smell" and no mastication and having unheated mouth... thus, releasing less volatile compounds... may have something to do with their poor olfactory function
True
It seems that the cat family cannot saturate linoleic and linolenic acids; thus, they need specific saturated FA of animal origin, such as arachidonic, eicosapentanoic, and docosahexanoic acids in their diet. In addition, the cat family cannot convert vitamin A to beta-carotene or synthesize tryptophan from niacin! Very interesting!
True
It seems that the fowl, especially young chickens and turkeys, cannot tolerate high dietary salts because of a couple of reasons. That is, they don't have bladder or urethra, and they do have limited ability to drink a lot of water
True
It takes about 580 cal of heat to change 1g of water from liquid to vapor, which can be important in dissipating excess body heat through, eg repiration and evaporation
True
It's amazing that each milliliter of the "rumen content" may contain, 10 to 50 billion bacteria, 1 million protozoa, and various members of yeasts and fungi!
True
Ketosis can be caused by inadequate oxaloacetate to utilize acetyl-CoA in the citric acid cycle. Unutilized acetyl-CoA can be, then, converted to ketone bodies, and excess ketone bodies, such as acetoacetate and beta-hydroxbutyrate, can result in ketosis
True
Lignin is a high-molecular weight, amorphous polymer of carbohydrate, which is important for the structural integrity of plant cell walls and some others. It is tightly wrapped around cellulose, and its hydrophobic nature might be important for transporting water in plants
False
Net effects of aldosterone? It can increase the Na retention and increase water in the intracellular fluid by eg increasing permeability to Na, ATP, and activity of Na pump, thus, restoring the blood pressure. It can also increase K excretion, which can lead to K deficiency under stressful conditions
True
Not much, but rumen fermentation can produce hydrogen sulfide, which is often associated with stored manure and can be deadly at 500 to 600 ppm! The problem is... we can smell it at a low concentration (1 to 5 ppm), but we would become insensitive to it very quickly... thus, we wouldn't even know whether gas is increasing or decreasing!
True
Obviously, it would depend on the type of fiber or its composition, but it seems that, at a low inclusion rate, nonruminant species are more efficient in the utilization of dietary fiber than ruminant species. Of course, it would depend on the composition of fibrous feedstuffs though!
True
Often, we use the term fat/fats, but it is better for us to use the term lipid/lipids. Why? Lipids include fats, oils, waxes, sterols, etc. that are not soluble in water, thus, very inclusive. in addition, "fat" contains glycerol and 3 FA, ie, it has a specific definition
True
Omega-3 or omega-6 FA? Well, simply, methyl carbon is known as w-carbon, and if a particular FA has the first double bond between 3 and 4 or 6 and 7 carbons from the methyl end, it would be called w-3 and w-6, respectively!
False
Pepsin is mostly responsible for intestinal digestion of protein, and it has 2 pH optima, 2 and 3.5. And, there would be no activity at all if the pH is >4
True
Perhaps, the most important factor in the digestion/absorption of long chain FA is the micelle formation, which can be affected by, among others, the degree of unsaturation, esterification, and chain length
True
Polyunsaturated FA may have beneficial effects on human health, but we just cannot forget that their double bonds are susceptible to auto-oxidation or peroxidation, which may have some adverse effects on, eg aging process and some sort of cancer
True
Protozoa? They are important for ruminant species in terms of the fermentation and growth and also the control of the bacterial population in the rumen becuase they are much larger and consume bacteria and use those as a source of energy and nutrients... thus, controlling the bacterial population!
True
Some proteins can be converted to VFA (e.g., valeric, isobutyric, and isovaleric acids) by microbes, but those are not a very important source of energy for the host
True
Some short and medium chain triglycerides or MCT can be utilized better vs. long-chain FA by, eg young pigs simply because those FA can be absorbed directly into the portal circulation without formation of micelle
True
Some signs associated with sodium deficiency? Salt craving may be associated with "tail biting" in pigs. Another sign? "Depressed appetite"... and some poultry producers are taking advantage of that to induce molting in laying hens
False
The "balance test" may be a good way to estimate the mineral requirement because a positive or negative balance would be a reflection of the dietary concentration or intake of the mineral in question
False
The duodenum is primarily a mixing site for all the nutrients. That is, bile, pancreatic secretions, etc. would be mixed with digesta in the duodenum, and not much digestion or absorption would take place in this part of the small intestine
False
The majority of nutrients are "digested and absorbed" at the upper portion of the small intestine, especially, at the jejunum, even though some nutrients can be absorbed at the lower portion... eg vitamin b12 at the colon or rectum
True
Water consumption? Although there are some variations because of various factors, most animals consume about 4-5 to 8-10% of their body weight! Also, we did mention that "never give water to "hot" horses on an ad libitum basis because it can lead to "hyponatremia!"
True
We can estimate the "protein" need for maintenance by considering endogenous urinary nitrogen (essentially, urea), metabolic fecal nitrogen, and growth of hair, nails, etc
True
We did mention that HDL-cholesterol is considered as a good cholesterol because HDL can remove cholesterol from cells and transport it back to the liver for, eg, excretion, whereas LDL cholesterol is considered as a bad cholesterol because LDL can, eg, contribute to the FA buildup in the arteries
True
We say that animals can lose nearly all of body fat, half of body protein, and 40% of body weight, and they can still survive! Water!? A different story! A loss of 6 to 8% may result in the nervous and metabolic disorders and animals may just die with a loss of 15 to 20% body water
False
We usually assume that most lipids are delivered to the duodenum without any changes in the nonruminant species because there is no lingual or gastric lipase. However, it is a bit different stody for the ruminant species because of the microbes in their rumen... which can, eg hydrolyze triglycerides to glycerol and free FA
False
What do we mean by beta-oxidation? Well, it refers to the removal of 2 carbons at a time from the methyl end of acyl-CoA, and the chain is broken between alpha (2) and beta (3) carbon atoms, thus, the term "beta-oxidation"!
False
When we need some energy/glucose, epinephrine can trigger a cascade sequence, which can cleave some beta-1,4 linkage to release glucose from glycogen by the action of phosphorylase a. By the way, glycogen contains beta-1,6 linkage too
False
When we're using urea as a protein supplement, we should also supplement ruminant diets with sulfur and branched-chain C-skeletons simply because those are necessary for the synthesis of sulfur and branched-chain amino acids, respectively
False
chickens do not have the "stomach" per se, but they do have their crop, proventriculus, and gizzard to accomplish gastric digestion. The only function of the crop is to store food, whereas the proventriculus secretes acid and enzyme and the gizzard grinds ingesta
True
in humans, obligatory urine production is associated with excretion of osmotically active solutes such as urea and salt, and we may need, at least, 600 mL of H2O each day for such a purpose alone
