Animal Nutrition Flashcards
(26 cards)
nutrient
the fundamental chemical constituents of food
nutrition
the sum of the processes concerned with the utilization of feed nutrients by animals
importance of animal nutrition
economics: feed often represents >50% of production costs on a livestock operation
prices have been very volatile in recent years
nutrition can impact product quality (marbling- intramuscular fat in beed, omega 3 fatty acids in eggs)
environment: greater production per animal has reduced the environmental footprint of animal agriculture
processes
first importance= maintenance (support of body proccesses)–> growth (increase in weight or size) –> reproduction (proliferation of species) –> animal products (used for human consumption) =last importance, high nutrient levels
feed nutrient
any substance found in food used for body function
6 classes of nutrients
5 classes of animal feed
classses of nutrients
water, carbohydrates, proteins, fats, minerals, and vitamins
water
most important nutrient for animals
need 3-4 times as much as solids
functions: nutrient transport, body temperature regulation, maintaining body fluids, lubrication
deficiencies can affect feed intake
water quality can affect intake: salt, sulfates, nitrates
acquired by: drinking, part of solid food, body metabolism
losses by: urine, feces, sweat and lungs
carbohydrates
primary role is to supply energy
major component of diet (%)
grasses, hay, grains
soluble(simple, alpha linkages–easier for body to break down) v. insoluble (complex, beta linkage)
soluble carbohydrates
simple, alpha linkages
monosaccharides= glucose
disaccharides= lactose
polysaccharides= starch
insoluble carbohydrates
complex, beta linkages
cellulose
hemicellulose
lignin -very hard to digest, structural components of plants-stems
proteins
building blocks of body
composed of amino acids
-essential: not formed in body in adequate amount, must be supplied in diet
-nonessential: formed in body, do not have to be in diet
shortage of any amino acid is limiting
proteins are 16% nitrogen, 1 in every 6.25 parts is N
analyze for N and multiply by 6.25 to arrive at protein value
ruminants can use non-protein nitrogen (NPN) if no more than 50% in diet (urea-elk, cows, etc)
fat
primary role is to supply energy
fat is 2.25 times as high in energy as CHO and protein
animals are limited in ability to use fat
other functions:
insulation
animal product quality (marbling)
energy partitioning
gross energy (GE)
\/—————————->fecal energy (FE)
\/
digestible energy (DE)
\/—————————-> urinary energy (UE). gaseous energy (GE)
\/
metabolizable energy (ME)
\/—————————->heat increment (HI)
\/
net energy (NE) –maintenance and production
measuring energy
gross energy (GE)
-heat of combustion
-intake energy
digestible energy or total digestible energy (TDN)
TDN= gross energy-fecal energy
metabolizable energy (ME)
ME= TDN- (urine and gas) or ME= gross energy- (feces, urine, gas)
net energy (NE)
NE= gross energy - all losses (maintenance, consumption, movement, and digestion
Nem (Net energy for maintenance) = metabolism, activity, heat, cool
Nep (Net energy for production) = growth, milk production, fattening, eggs, wool, work
Nei (net energy for lactation)
Neg (net energy for growth)
minerals
structure and balance
macrominerals
-need in large amounts (Ca, P, Na, Cl, S, Mg)
microminerals
-need in small amounts, trace minerals
-I, Zn, Mn, Co, Cu, Fe, Mo, Se, F
excess minerals are toxic
vitamins
catalysts and regulators
fat soluble
- A, D, E, K
-K is synthesized in rumen
-D is synthesized by sunlight on skin
water soluble
-B complex and C synthesized in rumen
five classes of feed
concentrate -grains
roughage/forage -grasses and hays
protein supplement
non-nutritive additives
vitamins/minerals
concentrates
high digestibility (80-90%)
high available energy
low fiber <18%
examples
corn, sorghum, barely, molasses, bakery by-products
roughages
less digestible (50-65%)
high fiber, cellulose
low available energy –> but can be utilized by ruminants
examples
hay, silage, grass, straw
why feed roughages? rumen function
protein supplements
feeds containing greater than 20% crude protein
contribute amino acids (nitrogen)
examples
soybean meal, meat and bone meal, urea, and fish meal
non-nutritive additives
works to increase gain efficiency
examples
antibiotics (minimize disease), ionophores (change rumen function–makes more efficient, makes safer to feed heavier grain diets), flavor compounds, hormone-like compounds (keep feedlot heifers out of heat (MGA))
vitamins/minerals
needed in very small amounts
-water soluble and fat soluble
-macro and micro (trace) minerals
proximate analysis
an approximation of the different nutrients in a sample
-dry sample down (moisture versus dry matter)
-dry matter (organic matter v ash (inorganic matter-mineral))
-organic matter (protein v non-nitrogenous matter)
-non nitrogenous matter (fat v carbs)
-carbs (crude fiber v nitrogen free extract)
Van Soest fiber system
system for describing chemical makeup of the fibrous components of feedstuffs
-defines properties of the plant cell walls
a. Neutral Detergent Fiber (NDF): isolates the cellulose, hemicellulose, and lignin (basically indigestible)
-negatively correlated to feed intake
b. Acid Detergent Fiber (ADF): isolates the cellulose and lignin components of the roughage
-negatively correlated to digestibility of the feed
