Principles of Animal Nutrition Exam 1

50-75%

Feed costs account for what percentage of production costs?

nutrition

The study of how the body uses nutrients in feed to sustain life and for productive purposes.

50-80%

What percentage of the total cost in livestock production is feed-related?

nutrient

A component of feed that aids in the support of life.

essential nutrients

Nutrients that are required in the diet because they can't be

synthesized in the body in sufficient quantities to satisfy metabolic needs.

feed

Any material, after ingestion by the animal, is capable of being digested, absorbed and utilized (not all is utilized).

feedstuffs

Any ingredients used as food for animals.

diet

An aggregate of multiple feedstuffs in a specific proportion to meet the animal's requirements.

ration

A food allowance for one day.

prehension

Taking in feed or water.

mastication

Reduction of feed particle size, generally by chewing.

deglutiton

Act of swallowing.

regurgitation

Return of undigested material from the stomach to the mouth.

digestion

Process of breaking down ingested feed into nutrients to be absorbed and utilized by the body for energy, growth, and repair; includes physical/mechanical, chemical, enzymatic, and microbial action.

absorption

Process where digested products are transferred from the small intestine into the bloodstream and lymphatic system.

metabolism

The sum of all biochemical processes that nutrients undergo to furnish energy and build new tissues.

anabolism

Growth or building process.

catabolism

Breakdown or destruction reactions.

excretion

Removal of waste.

carnivores

Species of animals that feed almost entirely on flesh of other animals.

omnivores

Species of animals that consume both plants and flesh.

herbivores

Species of animals that depend entirely on plants for food.

chemical (enzymatic) and microbial fermentation

What are the two methods that nutrients can be digested from feed?

physical/mechanical, chemical, enzymatic, microbial

What are the four combination of actions for digestion?

ingestion, digestion, absorption, egestion

What are the four phases of digestion?

monogastric

Having one stomach; also referred to as simple-stomached

or "non-ruminant".

ruminant

A mammal whose stomach has four parts, including the rumen, reticulum, omasum, and abomasum.

crop

What is an enlargement of the esophagus of poultry that has storage of feed, fermentation, and salivary amylase?

proventriculus

What is a glandular stomach in poultry that secretes gastric juices (pepsin) and hydrochloric acid?

gizzard/ventriculus

What part of the digestive anatomy of poultry grinds feed and reduces particle size and has strong muscular contractions?

small intestine

What part of the digestive tract of poultry is similar to mammals but in poultry, has no lactase?

ceca and large intestine

What digestive tract of poultry has water reabsorption, some fiber digestion, and water-soluble vitamin synthesis?

2-4 inches

How long is the large intestine of poultry?

cloaca

What digestive tract in poultry is a passageway for products of the urinary, digestive, and reproductive tracts?

foregut

What part of the digestive anatomy of the horse does the mouth, esophagus, stomach, and small intestine make up?

hindgut

What part of the digestive anatomy of the horse does the cecum, large intestine, small colon, and rectum make up?

foregut 30-40% and hindgut 60-70%

What percentage of a horses digestive system is the foregut and what percentage is the hindgut?

enzymatically

How are grains and concentrates digested in the foregut?

fermentation in the cecum

What does feed that is not digested in the foregut undergo and where?

1/2

A horse has _____ the stomach capacity of a cow?

coprophagy

Animals that depend heavily on cecal fermentation practice ________ for nutrient recycling or microbial digestion?

take in food, prehension, taste, chew, mix with saliva

What are the primary functions of the mouth?

water moistens feed and aids in taste mechanisms, mucin lubricates to aid in swallowing, sodium bicarbonate acts as a buffer to regulate stomach pH, amylase is a digestive enzyme that starts to break down simple sugars in the feed

What are the functions of water, mucin, bicarbonate salts, and amylase that are all secreted from the salivary glands?

top 1/3 is striated, middle 1/3 is striated and smooth, bottom 1/3 is smooth

Explain the top, middle, and bottom 1/3 of the esophagus.

peristaltic waves

Ingested material moves via muscular contractions known as what?

monogastrics have peristalsis going in one way where ruminants have peristalsis moving two ways, allowing for regurgitation

Explain the difference of peristalsis of monogastrics and ruminants.

stomach

What is a hollow, pear-shaped, muscular digestive organ that has storage of ingested food, a pH around 2-3, regulates gastric secretion, and muscular movements that cause physical breakdown?

gastrin, pepsinogen, rennin (chymosin), mucus

What are some of the juices that the stomach secretes?

rumen, abomasum, omasum, reticulum

Order the four compartments of the ruminant from the largest in volume to the smallest.

rumen

What part of the ruminant stomach is a hollow, muscular compartment that extends from the diaphragm to the pelvis and can nearly fill the left side of the abdominal cavity?

papillae

Walls of the rumen are lined with ______ and secrete no enzymes.

fermentation vat or paunch; 25 to 50

The rumen in referred to as the _____ or _____ and can hold up to _____ to ______ gallons of material.

fermentation

The rumen produces volatile fatty acids, methane, heat, B & K vitamins, and microbial crude protein due to what?

cellulolytic, hemicellulolytic, amylolytic, proteolytic, sugar and acid utilizing, ammonia producers, methane producers, vitamin synthesizers

What are the types of microbes in the rumen?

rumination

What is the process of bringing feed from the rumen back up to the mouth to be re-chewed?

regurgitation, remastication, resalivation, reswallowing

What are the four steps of rumination?

eructation

What is a very important mechanism for ruminants where microbial fermentation of feedstuffs in the rumen generates enormous quantities of gas (CO2 and methane)?

bloat

What will happen if a ruminant has trapped gas from lack of eructation that can result in death from asphyxiation?

omasum

What compartment of the ruminant is a spherical organ filled with muscular laminae, which are studded with short papillae and is located to the right of the reticulum and rumen; this functions to move particles from reticulum to

abomasum, absorption of water, reduction of particle size, continuation of grinding roughage?

many piles; 10 liters

What is the omasum usually referred to? What is the capacity of the omasum in liters?

abomasum

What is the first glandular portion of the ruminant, digest feed fractions not fermented in the rumen, digest bacterial cell proteins produced in the rumen, functions exactly like a monogastric stomach, glandular portion of the stomach, uses hydrochloric acid and enzymes to digest feed and nutrients (proteins)?

true stomach

What is the abomasum commonly referred to?

reticulum

What is not completely separated from the rumen and the walls are lined with mucus membranes containing many intersecting ridges which subdivide the surface into a honey-comb like surface with no enzyme secretions?

honeycomb

What can the reticulum be referred to as?

hardware disease

What is a common disease that occurs in the reticulum?

esophageal groove

The reticular groove, also known as the _______, is in young ruminants that is the transfer of milk from the esophagus to the omasum and abomasum but becomes non-functional after weaning?

liver

What organ contains bile salts and cholesterol?

bile salts

What component of the liver emulsify fats and activates lipase

gallbladder

Bile salts that emulsify fats and neutralize acidic chyme are stored in the what?

duodenum

What part of the small intestine receives secretions from Brunner's gland, the pancreas, and liver?

jejunum

What is an active site of nutrient absorption that has amino acids, sugar molecules, fatty acid, and glycerol?

ileum

What part of the small intestine is an active site for absorption?

cecum, colon, rectum

What are the three segments of the large intestine?

limited digestion with cellulases, hemicellulases, and pectinases in

the cecum and colon, fermentative digestion, absorption of water, VFA, vitamins, electrolytes, and minerals

What are the functions of the large intestine?

60%

What percent of the gastrointestinal tract is the large intestine of the horse?

cecum

What part of the large intestine has bacterial fermentation, bacterial breakdown of fibrous ingredients, synthesis of water-soluble vitamins and vitamin K, and proteins are considered of limited value to horses?

digestive hormones

What are chemical messengers released by cells in the digestive tract that regulate various functions of the digestive system, including secretion, digestion, absorption, and motility?

peptidase (peptides), lactase (lactose), sucrase (sucrose), maltase (maltose), chymotrypsin (protein), trypsin (protein), lipase (triglycerides or lipids), amylase (carbohydrate or starch)

What are the types of enzymes in the small intestine and their substrates?

lipids (fatty acids) or proteins (amino acids)

What cannot be absorbed in the large intestine?

ash/minerals

What makes up the feed component of inorganic matter?

carbohydrates, lipids, proteins, nucleic acids, organic acids, vitamins

What makes up the feed component of organic matter?

protein is broken down into amino acids; the amino acids undergo deamination which removes the amino group and produces NH3 (ammonia)

What happens to protein in the rumen, and what process converts amino acids into NH3?

rumen microbes use NH3 as a nitrogen source to synthesize microbial protein

What happens to NH3 in the rumen, and what important product can microbes make from it?

starch is broken down into soluble sugars, which are fermented by rumen microbes to produce volatile fatty acids (VFAs)

What happens to starch in the rumen, and what are the major products produced from it?

fiber is broken down into soluble sugars, which are fermented by rumen microbes to produce VFAs

What happens to fiber in the rumen, and what are the major products?

unsaturated fats are converted to saturated fats through biohydrogenation

What happens to unsaturated fats in the rumen, and what is this process called?

gastrin

What digestive hormone is secreted by G cells in the stomach and targets parietal cells?

CCK

What digestive hormone is secreted by endocrine cells of the small intestine and by neurons of the brain and gut and targets gallbladder, pancreas, and gastric smooth muscle?

secretin

What digestive hormone is secreted by endocrine cells of the small intestine and targets the pancreas and stomach?

gastric inhibitory peptide (GIP)

What digestive hormone is secreted by endocrine cells in the small intestine and targets beta cells of endocrine in the pancreas?

motilin

What digestive hormone is secreted by endocrine cells in the small intestine and targets the smooth muscle of the antrum and duodenum?

pp cells, gamma islet cells, beta islet cells, alpha islet cells

What are the four types of cells that secrete hormones in the pancreas?

glucagen

What pancreatic hormone is secreted by alpha islet cells, breaks down glycogen in the liver and muscles, and increases glucose levels in the blood?

insulin

What pancreatic hormone is secreted by beta islet cells, increases membrane permeability for glucose, lowering glucose levels in the blood, and excessive glucose oxidation in tissues?

somatostatin

What pancreatic hormone is secreted by gamma islet cells and inhibits release of gastrointestinal hormones?

pancreatic polypeptide

What pancreatic hormone is secreted by pp cells and self regulates the pancreas secretion activities and effects the hepatic glycogen levels?

amount and type of AA; energy content; composition of carbohydrates,

lipids, vitamins, and minerals; anti-nutritional factors and toxic

substances; ingredients of diets; methods of food processing; physical

characteristics of diets (e.g., temperature, particle size, color, smell, and

taste); the form of diet (liquid, pellet, or powder); and water quality

Explain how diet quality affects food intake of animals?

species (e.g., cattle, fish, horse, humans, pigs, poultry, and sheep), breeds (leghorn vs. broiler chickens; Meishan vs. offspring of Landrace × Yorkshire gilts and Duroc × Hampshire boars), and sex (males and females; boars vs. sows)

Explain how different species affects food intake?

age, pregnancy, and lactation; light, circadian clock, and melatonin;

release of hormones and satiety signals from the gut and brain;

concentrations of AAs, glucose, fatty acids, and their metabolites (e.g.,

ammonia, lactate, and ketone bodies in plasma and brain; and motility

of the gastrointestinal tract

Explain how physiological and metabolic factors affect food intake?

infection, trauma, neoplasia, diabetes, obesity, cardiovascular disease, fetal growth restriction, nausea, and vomiting

Explain how pathology affects food intake?