Quiz 5: Nutritive Value of Feedstuffs; Growth and Development; Reproduction

Factors Influencing Digestibility

*fiber content*, rates of passage, preparation and processing - will vary by animal

Relative Protein Values

- Eggs: 100 - Milk: 92 - Meat: 82 - Rumen Protein: 80 - Plants: variable

Vas deferens

- carries sperm cells and substances from the epididymus to the urethra - some species have enlarged portion called the ampulla (@ end)

Chemical Analysis - Van Soest

- has breakdown of fiber 1) Acid Detergent Fiber (ADF): contains cellulose and lignin; usually associated with digestibility 2) Neutral Detergent Fiber (NDF): contains cellulose, hemicellulose, & lignin; may contain intake (amt. animal may consume) * always higher because contains more components

Reproduction 4 stages

1) Gamete production: production of egg and sperm 2) Gamete maturation: ability to be functional 3) embryo development: after fertilization, growth of embryo 4) delivery: young animal leaves mother.

Controlling Mechanisms - short-term mechanisms

1) Monogastric animals a) gut-fill (physical) b) glucose (chemical) 2) Ruminant animals a) gut-fill (physical) b) VFA's (chemical)

Chemical Analysis - proximate

1) Water: determined by drying sample 2) Ether extract (EE): measures crude fat; most concentrated form of energy. 3) crude fiber - contains cellulose, lignin, and most hemicellulose 4) crude protein = N x 6.25 5) Ash: minerals 6) Nitrogen-free extract (NFE): obtained mathematically; mainly sugars & starches (some hemicellulose)

Prenatal stage

1) blastocyst - occurs after fertilization; nutrition is from uterine secretions and egg itself. 2) embryonic - cell differentiation into tissues and organs; very small increase in weight 3) fetal - major growth in weight and composition; nutrition is from maternal blood stream through placenta

Controlling Mechanisms - hypothalamus involvement

1) feeding center (appetite) - eat 2) satiety center - stop eating

Priority system for use of nutrients

1) nervous tissue, vital organs 2) skeletal 3) muscle 4) fat 5) reproduction (in preg. female - will take priority #2)

Factors that limit growth (postnatal)

1) nutrition 2) disease(s) 3) parasite(s)

TDN is determined by

1) proximate analysis 2) digestion trial 3) multiplying 1 and 2 together

Four phases post natal growth

1) short time after birth - head, neck, and legs - type of tissue: bone, muscle, and vital organs 2) early growth - body increases in length - type of tissue: bone, muscle, and vital organs 3) middle growth - increase in depth and width of body - type of tissue: bone, muscle, fat 4) late growth - additional development and width of body - development of loin and hind quarters - type of tissue: muscle, fat

Steps involved in determining nutritive value

1. Chemical Analysis 2. Palatability 3. Digestibility

energy deficiency

1. decrease in body weight 2 decrease in body fat emaciation 3. decrease in fertility 4. decrease in production

Growth curve post natal - a summation

1. different organs and tissues grow at different rates 2. different organs and tissues grow at different times 3. distribution of body parts and body comp. changes during life of animal (fat goes up, muscle goes down)

Scrotum functions

1. house and protect testicles 2. regulate body temperature of testicles (3-13 F) lower than body temp

Factors affecting compensatory growth

1. how severe is the nutrient restriction 2. how long did it occur 3. what time in their life was restriction

Factors influencing feed intake

1. physiological state 2. weight 3. activity level 4. temperature 5. disease status 6. palatability

Accessory sex glands functions

1. secrete nutrients 2. secrete buffers 3. secrete substances to cleanse & lubricate urethra - volume of semen produced depends on size of glands.

Accessory sex glands

1. seminal vesicles (vesicular glands): two 2. prostate: one 3. bulbo-urethral glands (Cowper's): two

Factors influencing prenatal growth

1. size of dam/ size of sire (genetics) 2. number of fetuses 3. implantation site in uterus 4. nutrition level of dam 5. disease status of dam (others - gender/sex)

Mature animal generally speaking eats ____ of its body weight per day

2-3%

Fats (lipids) have ___ more energy per gram than carbs or proteins

2.25

Average Daily Gain

ADG (W2-W1)/(T2-T1)

TDN (total digestible nutrients)

An estimate of energy content in feed - it really doesn't measure digestion

Protein Sources

Animal Sources - fish meal, meat scraps, meat and bone meal, blood meal Plant Sources - soybeans, cottonseed meal, etc.

Order of peaks in differential growth of major tissues graph

CNS (vital organs), Skeleton (bone), muscle, adipose (fat)

Energy - units

Calorie, Kilocalorie, Megacalorie

Calculation of Apparent Digestion Coefficient (ADC)

D/C = (Weight of Nutrient Consumed - Weight of Nutrient Excreted in Feces)/ Weight of Nutrient Consumed

Biological Partitioning - Digestible Energy

DE = GE - FE

Sometimes females won't go into heat. Why?

Energy is used for nervous tissue, vital organs, skeletal, muscle tissue, and fat

Biological Partitioning - Gross Energy

GE: total amount of energy - always largest

What sets the maximum mature size and rate of growth?

Genetics. All other factors determine the proportion of maximum that will be obtained.

Monogastrics (average quantities and kinds of feed)

Grains, concentrates 2-6% of BW/day very young could be up to 13%

Biological Partitioning - Metabolizable Energy

ME = GE - FE - UE - GPDE * energy available for use in cells used to calculate birds energy. can't differentiate between UE and FE because cloaca mixes them

Biological Partitioning - Net Energy

NE = GE - FE - UE - GPDE - HI * always smallest * available energy for maintenance, growth, and lactation (accounts for energy used in consumption and digestion of foods)

Growth velocity curve, what is the peak?

Puberty

Ruminants (average quantities and kinds of feed)

Roughages 1-3%. of BW/day ** probably 2-3%

Postnatal stage

Shape - sigmoid a) self-accelerating: initial exponential phase of growth b) self-inhibiting: growth slows because of restraints

Chemical Analysis - NIR (Near-Infrared Spectroscopy)

Spectroscopy - rapid method using infrared lights to analyze bonds in feeds and determine moisture, fat, protein etc.

Measurements of growth and development

Weight, height, length, body composition

Compensatory growth

a period of accelerated growth that follows a time of nutrient restriction

Epididymis sections

a) Head (top of testicle) b) Body c) Tail (bottom of testicle)

Protein Quality

a) chemical procedures: amino acid analysis b) biological procedures: biological value (BV) - BV = N retained/N digested x 100 c) relative protein values d) protein sources

Testicles - Types of tissue and function

a) interstitial: cells of Leydig produce testosterone which gives male characteristics (ex. antlers on deer, crested neck of bull) - interstitial is between seminiferous tubules b) seminiferous tubules: spermatogenesis occurs, tubes are very long 1/2 to 1 mile uncoiled

Influences of sex hormones

a) mature size: M>F b) rate of growth: M>CM>F c) rate of fattening: - cattle & sheep F>CM>M - swine CM>F>M d) feed efficiency: M>CM>F e) Carcass Characteristics - lean: M>CM,F (testosterone effect) - fat: F,CM>M

Factors influencing energy requirements

a) species b) age c) activity level d) production levels e) temp (environmental) f) nutritional deficiencies h) surface area of animal

Semen composition

a) spermatozoa b) secretions - quantity and concentration varies by species - accessory sex glands - vas deferens - epididymus * higher volumes of semen have lower concentrations of sperm per mL of ejaculatory fluids

epididymus functions

a) storage of sperm cells b) provision of maturation space of sperm cells b) nutrition of sperm cells through secreted substances

Avian male differences in reproductive structures

a) testicles - same b) epididymus - same c) vas deferens - conducts semen into cloaca area.

factors encouraging growth: Genetic Hormones - growth of specific organs

a) thyrotropin (TSH): from anterior pituitary, targets thyroid b) adrenocorticotropic (ACTH): targets adrenal cortex c) gonadotropins: targets gonads 1) follicle stimulating hormone (FSH) 2) luteinizing hormone (LH)

factors encouraging growth: Genetic hormones - permissive for growth

a) thyroxin - from thyroid, sets metabolic rate b) insulin - from pancreas; promotes cell division c) adrenal corticoids: from adrenal glands

Protein Quantity

a) total protein b) digestible protein

Tumors

abnormal localized cell growth without normal control mechanisms

Regulating feed intake

animals eat to meet energy requirements - see diagram pg. 92

Lipostatic theory

appetite is regulated by fat reserves - applies to hibernating animals

Atrophy

cells start to shrink

Testicles - location and migration

descend through inguinal canal to the scrotum around time of birth **chicken = exception

Appetite

desire to eat

Chemical Analysis - complete

done in lab; looking at every amino acid, mineral etc.

Consequences of having to much protein

expensive, growth is good, excess H2O intake

Vitamins

expressed as international units (IU's - fat soluble), mg, etc.

Minerals

expressed as ppm, % mg, etc - macrominerals in animal carcasses at greater than 100ppm

Leptin control of appetite

from adipose (fat) tissue * decreases appetite

Neuropeptide Y (NPY) control of appetite

from hypothalamus * increases appetite

Cryptorchidism can be

genetically transmitted

Somatotropin

growth hormone from pituitary - increase cell growth, mitosis, and protein production and stimulates bone growth (growth plate)

Glucocorticoids

help regulate carbohydrate conversions + metabolism

Hyperplasia

increase in cell numbers (early, prenatal stage)

Hypertrophy

increase in cell size (after birth)

CCK control of appetite

influences hypothalamus * decreases appetite

Satiety

lack of desire to eat

Concentrates

less than 18% crude fiber

Consequences of having to little protein

lower growth, decreased efficiency

Roughages

more than 18% crude fiber

Bomb Calorimeter

obtains gross energy (GE) of feed

Passageway for urine and sperm

penis is the origin of copulation for males. Urethra is a large canal in the penis

mineralocorticoids

regulate concentrations of minerals especially Na + K

Byproduct feeds

result from manufacturing process ex. distiller's grains (alcohol product), brewer's grains (beer product)

sigmoid flexure

retractable muscle controlled presentation of the penis. Seen in pigs sheep cattle and goats. Bone = dog

Variations in semen (avian male) compared to mammals

semen is more concentrated and has a lower volume than mammals (missing accessory glands)

Digestibility - definition

the ability of a nutrient to be digested and absorbed by the animal rather than be eliminated by the feces

Epididymis anatomical relationship to testicle

the head of the epididymus connects to the seminiferous tubules through efferent ductules

What are the limitations of complete, proximate, and NIR chemical analysis?

they do not tell about palatability, toxicity, or digestibility.

cryptorchidism

unilateral: one testicle does not descend through the inguinal canal bilateral: neither testicle descended from inguinal canal - definite reduction in testosterone levels - much lower fertility

Breeding Soundness Exam (BSE)

used to see if both testicles have descended