exam 3

how are poultry nutritionally unique from other monogastrics

two ceca, crop, proventriculus, ventriculus, short digestive system, beak with little tongue, grind feed in the gizzard

which amino acids are of particular significance to poultry

methionine for feather production, glycine and arginine for uric acid

why are calcium and phosphorus requirements of poultry relatively high

bone strength for broilers and shell quality in layers

how does pellet quality affect ADFI, F:G, and energy retention

if pellet falls apart more energy is used to pick up the pieces, instead of muscle

what special issues are involved with feeding laying hens

limestone is heavy and is hard to move down the feed trough

what special issues are involved with feeding turkeys

prefer crumbles, dont over feed salt, Ca and P are needed for bone strength

unique aspects of poultry nutrition

digest raw starch, no issue with diet palatability, adjust feed intake to meet energy needs, excellent feed efficiency 1.90:1

mammal urea cycle

arginine is synthesized during urea production and not needed in diet

what do bird produce instead of urea

uric acid, arginine is needed in diet, production of uric acid requires catabolism of glycine

what affects muscle mass

gender and genetic strains

factors that affect ADFI, ADG, and nutrient requirements

muscle mass, age, ambient temperature, pellet quality

muscle mass

amino acid requirements increase with muscle mass

how does age affect ADFI, ADG, and nutrient requirements

requirement for aa, Ca, and available P decrease and the requirement for energy increases as a bird approaches market weight

ambient temperature

intake and energy requirements may change when ambient temperature is outside of the bird’s thermoneutral zone

pellet quality

intake decreases and energy requirements increase when pellet quality is poor do to birds lack of peristalsis

capon

castrated chicken

reducing particle size for birds

improves starch digestion, 800 microns or greater

how should pellets be for birds

firm enough to go through handling but break apart once eaten

order of limiting aa in bird diets

methionine, lysine, threonine, isoleucine

methionine in poultry

usually added to corn-soybean meal diets

cysteine in poultry

significant component of keratin, a protein in feathers

glycine in poultry

requirement is high for the uric acid cycle

diets feed during the 6-week growing period

starter, grower, finisher, occasionally and a pre-starter or withdrawal diet for antibiotics

egg-laying chickens compared to broilers

diets low in protein, energy, processing costs, high in Ca

cottonseed meal

free gossypol forms complexes with iron and causes olive colored yolks

rapeseed meal and canola meal

trimethylamine results in off-flavored eggs

fish meal

fish oil results in off-flavored eggs

egg yolk pigmentation

carotenoid pigments are yellow-orange yolks, yolk color is only an issue for people who eat them

xanthophyll sources

alfalfa and marigold

feeding turkeys

marketed at 14-15 weeks for hens, 17-22 for toms, F:G 2.5:2.8, 6 phase fed diets

fist limiting aa in turkeys

methionine and cysteine

order of energy sources

blood glucose, glycogen in liver and muscle, fat

special issues with turkeys

feed crumbles, low liver glycogen and vitamin E, rickets and leg weakness is common, ascites

ascites

fluid accumulation in the peritoneum, caused by elevated salt levels or growing very fast

what are the key differences in nutritional management of companion animals and livestock

longevity is the goal, not trying to make a profit, other concerns with pets

what key factors differentiate pet foods from one another

what protein is used, amount of marketing, additives and type of formulas

list the factors that affect nutrient requirements of companion animals

activity level, age, body size for maintenance, shape of the animal, genetics

what are the functions of dietary fiber in pet foods

help them fill full, slow down digestion, control blood sugar, stool consistency

list the key issues with protein nutrition of pets

more digestible, carry more minerals if a byproduct feed

list the key issues in mineral nutrition of pets

kidney problems

generic pet food

juvenile, adult, senior

specialty pet food industry

weight control, urinary health, dental health, odor control, joint health, dermatitis

distinguishing features of pet foods

quality control, ingredient quality, ash content, research and development, marketing emphasis, protein characteristics, and cost

ash content

mineral content

common features of pet foods

not least-cost formulations, little is known about nutrient requirements, generally exceed nutrient requirements

high animal protein in pet food

typically poultry meal, meat and bone meal, and offal from packing plants

offal

intestines

vitamin additions in pet food

cover full range of vitamins and is typically exceeded

concerns in pets

quality of life, coat appearance, stool volume, longevity, disease prevention, wellness

energy level requirements for pets

relatively low

factors affecting requirements

activity level, gender status, genetics, health status, life stage

life stage nutritional issues

development orthopedic disease, progressive renal disease, dental disease, obesity

fatty acids in pets

high energy reduces nutrient excretion, hair and coat quality, nervous tissue development, platelet aggregation, prevention of mineralization of kidneys, brain and retina function, short chain improves gut health

dietary fiber in pets

satiety, management of diarrhea and constipation and blood glucose, poorly digested

protein in pets

high percent of aa, low ash content so P can be controlled

what does high phosphorus in pet diets cause

mineralization of kidneys

cat essential aa

taurine

taurine deficiency leads to

abnormal heart function, retinal structure problems, insufficient bile, reproductive failure

animal protein sources for pets

highly digestible, labeling and marketing advantages, generally poor protein:ash ratio

plant sources in pet diets

less digestible, no taurine, less marketing appeal, good protein:ash ratio

vitamins in pet diets

A, E, and C added for immune system function and to support rapid muscle growth

minerals in pet diets

Ca and P to support skeletal development, low Na for blood pressure and heart maintenance, low Mg to minimize kidney ailments

ammonium phosphate crystals in urine

commonly called struvite crystals, to prevent in young cats and dogs diets acidified and Mg concentrations kept low

calcium oxalata crystals in urine

commonly called oxalate crystals, to prevent in old dogs and cats diet pH and Mg increased

what is fed to promote cartilage repair

glucosamine and chondroitin

most abundant carbohydrate on earth

cellulose

starch comes from

grain and is glucose bonded by alpha bonds

cellulose comes from

forages and is glucose bonded by beta bonds

factors that influence forage quality

plant maturity, forage type, plant part, selective grazers

plant maturity

nutritional quality decreases as plant matures

forage type

nutrient content and nutrient availability vary across plant species

plant part

leaves more nutritious than stems and shoots

selective grazer

grazing animals select plants and plant parts that they prefer when given the opportunity

forage types

grasses, forbs, brows, crop residue

grasses

cool season vs warm season, annuals vs perennials, cultivated vs native

C3 plants compared to C4 plants

C3 has more protein, greater protein degradability, less fiber and lignin, greater energy availability

lignin

fiber component of plant and is indigestible

forbs

broad leafed, non-woody plants, non-legumes vs legumes

forbs compared to grasses at similar maturity

more protein, better protein degradability, less fiber and more lignin, similar energy content

non-legumes

not associated with symbiotic rhizobia, do not fix atmospheric nitrogen, most are native species

legumes

rhizobia fix atmospheric nitrogen, increase soil fertility, native cultivated varieties, many can cause bloat when grazed

browse

woody plants, leaves from shrubs and trees, most are native, preferred by goats, maintain nutrient quality for longer periods, high levels of tannins

crop residue

corn or milo stubble, high fiber, low protein, nutritive value depends on the amount of grain in residue

selective grazers

usually pick leaves which are more digestible, depends on maturity and plant species

what is selection driven by

plant palatability, plant growth form, cattle experience

nutritive value of forages

less starch but more fiber, abundant energy for ruminants and horse, highly variable nutrient content

how to find nutritive value of forages

physical evaluation and color are not good indicators, take a sample and send it out

van soest dtergent system of fiber analysis

neutral detergent solution removes cell contents, acid detergent solution removes hemicellulose, sulfuric acid removes cellulose, want low levels of lignin left over

cell contents

rapidly degraded by microbial microbes, digestibility is near 100%

cell wall

lignin is largely indigestible, digestibility of hemicellulose and cellulose fractions are influence by their physical association with lignin

as forages mature

cell wall content increases, digestibility decreases, protein content decreases dramatically

neutral detergent fiber

NDF, contains hemicellulose, cellulose, and lignin

acid detergent fiber contains

ADF, cellulose and lignin

ADF helps dtermine

digestibility of a forage

NDF helps determine

intake of a forage

acid detergent insoluble nitrogen

ADIN, a system for estimating protein availability from forages based in detergent fiber analysis

protein availability as measured via ADIN

reflection of heat damage incurred during preservation and storage

reduction of forage particle size

increases intake of forages by ruminants

rate of forage digestion

increases as particle size is reduced

rate of passage increases

as forage intake increases