animal nutrition lab 1

impacts of animal nutrition

protein content, fat content, food safety, color & shelf life, meat quality-consumer, environmental impact

nutrient classes

carbohydrates, water, proteins, lipids, minerals, vitamins

nutrients

dietary essentials for one or more species of animal. it may be assumed that a particular nutrient may not be considered essential for all species

animal nutrient response graph

average daily gain

average amount of weight a market animal will gain each day during the feeding period

average daily gain formula

amount of weight gained since last measured/number of days since last measured

factors influencing ADG

growth implants, ionophores, genetics (continental breeds vs other breed groups, progeny differences), environmental influences (post weaning stress, heat and humidity), diet (forage or concentrate rations)

a pig must weigh 230 lbs. at slaughter, currently weighs 181 lbs., and is gaining 2.2 lbs. per day. how many days will it take to make market weight? round to a whole day.

how many lbs does the pig have to gain? target-current= 230 lbs-181 lbs  →49 lbs. days? lbs needed/ADG→ 49lbs/2.2lbs/day→22.27 days. =~23 days

feed efficiency

feed to gain ratio. amount of feed (dry matter) required to gain one unit of gain. as animals grow, daily feed intake will increase, but they will become less efficient in converting the feed into weight gain (more put into body maintenance than growth at a certain point)

feed efficiency formula

total lbs of feed per day/average daily gain

why is ADG and FE important

ultimately ties back to how the animal is fed and the effectiveness of the nutrition program. nutritional analysis and genetic potential of the animal plays a huge part in productivity. total cost to finish

digestion

digestive tract of any animal is important in converting the food the animal eats into nutrients their body needs for maintenance, growth, and production. once food is eaten, it must be broken down into its basic components: mechanical (typically involves chewing) and chemical (release of digestive enzymes)

mouth

tongue. sublingual, mandibular, parotid salivary glands work together to create saliva. saliva

tongue

serves as the first step to generate saliva and it helps push food toward the esophagus.

saliva

watery, mucus-like secretion of the salivary glands in the mouth that lubricates the food and aids in digestion. contains an amylase that helps break down starch

esophagus

tube that carries food from mouth to stomach. muscle contractions push food toward stomach. swallowing is the first of the contractions. cardiac valve

cardiac valve

at the end of the esophagus, prevents food from passing from the stomach back into the esophagus

stomach

reaction chamber where chemicals are added to the food. certain cells along the stomach wall produce hydrochloric acid and enzymes (help break down food into small particles). pyloric valve

pyloric valve

particles that the stomach cannot absorb into the bloodstream pass into the small intestine through the valve

accessory organs

gall bladder, bile. liver. pancreas

gall bladder

storage compartment for bile

bile

secreted by liver, stored in gall bladder. assists in the digestion of fats

liver

secrete bile

pancreas

secretes juices that aid in the digestion of fats, carbohydrates, and proteins. secretions added in the duodenum

small intestine

assists in absorption of nutrients. 3 parts: duodenum, jejunum, ileum

cecum

between ileum and large intestine is a “blind gut”. no primary role for it in swine, but in some monogastric animals aids in digestion of fibrous material. carbohydrate breakdown

large intestine

main function is absorption of water. mucous added to remaining food to make passage easier. colon. peristalsis. rectum & anus

colon

largest portion of large intestine and plays a major role in water absorption and formation of feces

peristalsis

series of wave-like muscle contractions that move food through the digestive tract

rectum

final portion of the large intestine. straight tube out of the large intestine that forms solid waste. final site for water absorption

anus

final part of the digestive tract to excrete undigested food from the body

hindgut fermentation cecum (horses)

higher fiber intake. microbes in cecum must act to break down cellulose and hemcellulose (microbes have specialized enzymes)

avian intake

digestion begins at mouth and ends at cloaca. beak is used to obtain food (saliva secreted to aid in digestion and intake of nutrients). tongue is used to push food to the back of the mouth. esophagus carries food to the crop

crop

outpocketing of the esophagus in the neck region. primarily a temporary storage pouch. can become impacted in a chicken that is free-ranged on a pasture of fibrous vegetation

proventriculus

connected to crop, true stomach. glandular region where digestion begins. hydrochloric acid and pepsin interact to begin digestion

gizzard/ventriculus

unique to birds. mechanical stomach acting as the birds teeth made up of 2 muscles. chickens eat small stones used to grind feed mixed with the acidic condition produced in proventriculus

avian small intestine

recieves digestive enzymes and produces bicarbonate to counter acidic conditions. bicarbonate produced by pancreas. bile produced by liver and stored in gallbladder. bile: detergent that’s important in lipid digestion. duodenum, jejunum, ileum

avian ceca

plural for ceca, 2 blind pouches where small and large intestines join, fermentation of any remaining materials

avian large intestine

aka colon, shorter than small intestine, last of water re-absorption occurs here

cloaca

mixing of digestive wastes with urinary wastes. reproductive tract also exists but when an egg is laid the vagina folds over to allow the egg to leave through the vent without coming into contact with the waste material. vent

vent

outermost portion of cloaca, keep waste material out of reproductive tract

cattle prehensile tools

cattle harvest forages during grazing by wrapping their tongues around the plants and then pulling to tear the forage for consumption.

on average, cattle take from ______ to more than ______ prehensile bites to harvest forage while grazing each day.

25,000 to 40,000

cattle spend _____ of their day grazing, _____ of their time ruminating (cud chewing), and slightly less than ______ of their time idling where they are, neither grazing nor ruminating.

more than one third, one third, slightly less than one third

ruminant mouth

roof of the mouth is a hard/soft palette without incisors. lower jaw incisors work against the hard dental pad.

incisors of _________ selectors are wide with a shovel shaped crown, while those of _________ selectors are narrower and chisel shaped. 

grass/roughage, concentrate

ruminant saliva

most important function is buffer rumen pH levels in reticulum and rumen

does not contain enzymes for breakdown of fat (salivary lipase) and starch (salivary amylase) like monogastrics!

ruminant salivary glands

mature cow produces 50 quarts per day. depends on the amount of time spent chewing feed, because that stimulates saliva production

will a steer that’s fed concentrate salivate more or less than a steer on a 100% forage ration?

forage ration: ruminating and rechewing more. chewing motion stimulates salivary glands

ruminant esophagus

bolus moves from mouth to the reticulum. muscle contractions and pressure differences carry substances down to the reticulum. functions bidirectionally in ruminants, allowing them to regurgitate their cud for further chewing

forage and feed mixes with saliva containing sodium, potassium, phosphate, bicarbonate, and urea when consumed to form a ____

bolus

rumination

“cud chewing”. where forage and other feedstuffs are forced back into the mouth for further chewing and mixing with saliva

true ruminants

cattle, sheep, goats, deer, antelope

T/F: ruminants have four stomachs

False

true ruminants have: 

one stomach with four compartments

ruminant stomach compartments

reticulum, rumen, omasum, abomasum

rumen and reticulum comprise ____% of the volume of the total stomach. the omasum occupies ___%. The abomasum occupies ____%

84%. 12%. 4%

the _____ is the largest stomach compartment, holding up to 40 gallons in a mature cow

rumen

reticulum

cud is re-swallowed and passed into reticulum. solid portion slowly moves to rumen for fermentation, while most of the liquid portion rapidly moves from the rumen. “honeycomb”. sits underneath and towards the front of the rumen, lying against the diaphragm.

reticulum holds approximately _____ gallons in the mature cow

5

reticulorumen

typically, the rumen and reticulum are considered one organ because they have similar functions and are separated only by a small muscular fold of tissue

reticulum nickname

honeycomb

main function of the reticulum

collect smaller digesta particles and move them into the omasum (large particles remain in the rumen for further digestion)

reticulum traps and collects heavy/dense objects the animal consumes.

when a ruminant consumes a nail, wire, or other sharp heavy object, it is very likely the object will be caught in the reticulum. object can penetrate the reticulum wall and make its way to the heart, where it can lead to hardware disease. 

ruminant stomach compartment order

reticulum, rumen, omasum, abomasum

rumen main function

fermentation vat by hosting microbial fermentation

rumen pH

6.5-6.8

rumen nickname

“paunch”

rumen

lined with papillae for nutrient absorption and divided by muscular pillars. solid portion left behind here typically remains for up to 48 hours and forms a dense mat in the rumen. microbes are densely packed here and use the fibrous feedstuffs to make precursors for energy

rumen microbial fermentation products

gas and VFAs

rumen microbes and VFAs

rumen is home to a population of microorganisms that include bacteria, protozoa, and fungi. these microbes ferment and break down plant cell walls into their carbohydrate fractions and produce volatile fatty acids. animal later uses the VFAs for energy.

VFAs

acetate, propionate, butyrate

acetate

fat synthesis

propionate

glucose synthesis

butyrate

carbohydrates

omasum

spherical and connected to the reticulum by a short tunnel. many folds or leaves, increase surface area , which increases the area that absorbs nutrients from feed and water

omasum function

water absorption

omasum nickname

“many piles” or “butcher’s bible”

abomasum other name

“true stomach”

abomasum pH

3.5-4

____ cells in the abomasum secrete mucus to protect the abomasal wall from acid damage

goblet

abomasum function

chemical and enzymatic digestion. produce hydrochloric acid and digestive enzymes (pepsin, pancreatic lipase)

pepsin

breaks down proteins

pancreatic lipase

break down fats

ruminant small intestine

up to 150 feet long with a 20 gallon capacity in a mature class. digesta entering sm intestine mix with secretions from the pancreas and liver, which elevate the pH from 2.5 to between 7 and 8. bile from the gall bladder is secreted into the first section of the small intestine (the duodenum)

ruminant large intestine

absorbs water from material passing through it and then excretes the remaining material as feces from the rectum. final site of any remaining water absorption is the rectum and the digesta is excreted

site of most water absorption in ruminants

colon

ruminant cecum

large blind pouch at the beginning of the large intestine, approximately 3 feet long with a 2-gallon capacity in the mature cow. serves little function in ruminants