Principles of Animal Nutrition Test 1, Sec. 1

nutrition

a process that a living organism consumes food and uses it for growth, tissue repair, tissue replacement, elaboration of products

growth, tissue repair, tissue replacement, elaboration of products

nutrition is a process that a living organism consumes food and uses it for:

nutrient

any component of the diet that supports normal growth, reproduction, lactation or maintenance of life

essential or indispensable

nutrients that cannot be synthesized by the body are termed...

food

any edible material that provides nutrients for humans or companion animals like dogs, cats, etc.; (ex. rice and beans made into a meal)

feed

any edible material that provides nutrients for animals

feedstuff (foodstuff)

any substance made into or used as feed or food, respectively; (any ingredients in food; ex. rice by itself)

diet

a mixture of feedstuffs used to provide nutrients to animals

ration

a daily allocation of feed or food

simple compounds and complex mixtures supplied by some plant and most animal products

animal feed contains:

vitamins

most expensive component in the diet

macro- and microelements

may be present at toxic levels in some plant tissues; can be toxic when ingested in excessive amounts

fat and carbohydrate

animals contain higher concentrations of \___ and very low concentrations of \___ (less than 1%)

60% water, 20% fat, 16% protein, and 4% minerals

body composition of an adult mammal

farmers and animal feeders, scientists and technologists, and nutritionists and veterinarians

the science of nutrition is developed by:

science of nutrition

has grown rapidly because of the availability of variety of models, such as cell cultures or animal models

40

today, we know more than \___ nutrients are required in the animal diet

water, proteins and amino acids, carbohydrates, lipids, vitamins, and inorganic elements

what are 6 groups of nutrients?

proteins and amino acids, carbohydrates, and lipids

out of the 6 groups of nutrients, which ones are energy producing?

amino acids

molecules that combine to make proteins

lipids

gives you the most energy; end up in lymphatic system

essential are added/required in the diet and nonessential are made in the body

what is the difference between essential and nonessential nutrients?

species, selection of traits within species, age of the animal, productivity, the dietary constituents available, and other factors

what factors do influence the animal's nutrient requirements?

proteins containing amino acids, non-protein nitrogen-containing compounds, lipids, carbohydrates, vitamins

what materials make the organic components of animal's feed?

macro- and micro-(trace) elements

what materials make the inorganic components of animal's feed?

structure of digestive tract tells us what kind of nutrient requirements the animal needs

why do we need to learn about digestive physiology of animals?

digestion

preparation of the digest for absorption (getting ready for the absorption of nutrients)

absorption

the passage of small molecules from the lumen of the GI tract into the blood or lymph systems (have this in the stomach which includes some minerals)

chewing food, GI tract muscular contractions, mixing digesta with chemicals, enzyme hydrolysis of nutrients

digestion includes:

ingestion and digestion of food and elimination of the wastes

the GI tract is a tubular structure used for:

mouth, esophagus, stomach, and small and large intestine

what are the major digestive organs?

associated digestive organs

not major digestive organs

liver and pancreas

what are the associated digestive organs?

liver

secretes bile into the small intestine; plays an important role in digestion, absorption and metabolism; produces bile that functions in emulsification (the process of breaking down the fat into smaller blood cells) of lipids and micelle formation for improved absorption of lipids

pancreas

secretes digestive enzymes into the small intestine; one of the key organs to help in digestion; releases its secretions directly to the duodenum via a pancreatic duct; can digest lipids; produces numerous saccharidases which are important in hydrolyzing starch, glycogen, or dextrins to maltose (malt sugar which is a disaccharide and tastes less sweeter than table sugar)

cardia, fundus, and pyloric

what are three distinctive anatomical regions of the interior stomach?

esophagus, cardiac sphincter (gate), cardia, fundus (body), pyloric, pyloric sphincter (gate)

order of mucosal tissues lining the stumach

body chief/peptic cells and parietal/oxyntic cells

what types of cells can be found in the fundus of stomach?

body chief or peptic cells

produce proteolytic enzymes (break down proteins)

parietal or oxyntic cells

secrete hydrochloric acid

small intestine

main site of absorption; most of the absorption in the GI tract occurs here; longer for herbivores because they consume more fiber than carnivores and it needs more time to digest; pigs have a comparatively long one (15-20 m), but dogs have short one (4 m); covered with fingerlike projections called the "villi"

villi

increase the absorptive surface area of the small intestine; fingerlike projections that cover the small intestine

arteriole, venule, and lacteal

what are the three vessels found in each villus?

arteriole

small blood vessels that carry blood away from your heart

venule

drains into the portal blood system

lacteal

a drainage of the lymphatic system

portal system

takes blood from lower part of body and brings it up

carbs and proteins

end up in portal system

cardia

the cells produce mucus to protect the lining from gastric secretions (this is important to protect the wall of the stomach from hydrochloric acid); it is the first part of the stomach, which is connected to the esophagus; it contains the \___ sphincter, which is a thin ring of muscle that helps to prevent stomach contents from going back up into the esophagus

fundus (peptic gland region)

contains gastric pits, which open into gastric glands; it stores gas produced during digestion

pyloric

the cells produce mucus to protect the lining from gastric secretions (this is important to protect the wall of the stomach from hydrochloric acid); contains the \___ sphincter at the bottom of the stomach which governs the passage of food out of the stomach into the small intestine

duodenum

first section of the small intestine that produces various digestive secretions; digestive secretions from the pancreas as well as bile are released; some amount of absorption may occur

duodenum, jejunum, ileum

what are 3 segments of small intestine?

jejunum and ileum

absorption in the small intestine mainly occurs here; different nutrients are absorbed from different sides; the last section is the most active section of nutrients absorption

cecum, colon, and rectum

what are 3 segments of large intestine?

large intestine

the size of sections vary considerably among species (it is not longer, it is wider, bigger in diameter); functions as an area for absorption of water and secretion of inorganic elements; full of microbial cells

horses and rabbits

have a large cecum

cecum and colon

considerable amount of bacterial fermentation occurs here

synthesis of some of the water-soluble vitamins (B&C), amino acids, and volatile fatty acids

what is the role of bacterial fermentation in the cecum and colon?

volatile fatty acids (VFA)

can evaporate at room temperature; really tiny

fat

hydrophobic, they don't like water, that's why they need biles; small fractions can be covered by biles which allows them to move along the GI track; horses, rats, moose, etc. can still digest this because the liver produces biles, but they can't have to much because they have nowhere to store it, they don't have a gallbladder

bile

a type of salt produced by liver cells and stored in gallbladder

crop

in avian species, first part of GI tract with storage and fermentation functions

proventriculus

the site for production of gastric juices

ceca

two branches of cecum; plural; some fiber digestion through bacterial fermentation occurs

gizzard/ventriculus

have similar functions of teeth in mammalian species; has strong muscles covered in protein called koilin

koilin

strong muscles covered in protein found in the gizzard/ventriculus

crop, proventriculus, gizzard/ventriculus

what are 3 compartments of stomach in birds?

small intestine enzymes and absorption in avian species

similar to the ones in mammals (lactase is absent); lactose is found in sugar and milk, don't need lactase bc milk is not in their diet

ceca and large intestine

major sites for resorption of water in avian species

ruminants

have no upper incisor teeth, but a few species have canine teeth; lamas and alpacas use their teeth mainly for fighting; use upper dental pad and lower incisors, lips and tongue for grasping food; have shaped and spaced molar teeth to chew on only one side of the jaw at one time; produce copious amounts of saliva (150 L/day in adult cows and 10 L/day in sheep); an even-toed ungulate mammal that chews the cud regurgitated from its rumen; ex. cattle, sheep, antelopes, deer, giraffes, and their relatives

roughage eaters (cattle and sheep), selective eaters (goats), and transitional types (elk and deer)

ruminants are divided into:

lateral jaw movements

aid in shredding tough plant fibers in ruminants

non-ruminants

animals with a single-compartment stomach, such as swine, poultry, horses, dogs, cats, and humans

amylase

an enzyme that is a type of protein that helps your body break down carbohydrates; ex. of digestive enzyme found in saliva; source is either saliva or pancreas

saliva

has amylase; secreted during mastication mainly from three bilateral pairs of glands; important roles: acts as a buffer and is a source of nutrients

a source of N, P, Na, and a strong buffer that maintains the appropriate pH in the rumen

what are the physiological functions of saliva in ruminants?

buffer

it resists dropping down the pH, helps maintain pH; invert the low pH of dental plaque, and permit oral clearance, therefore removing the enamel demineralization

6.7

what number is the pH of ruminants around?

acidosis

can be caused if the pH is as low as 3 or 4, can cause lameness, etc.

stomach

may contain 65-80% of the digesta in the entire GI tract; (transit time for ruminants is more than 72 hours, can take 3 to 4 days); (amylase is important for ruminants)

it breaks down fats to fatty acids

what is the role of bile in fat digestion and absorption?

reticulum, rumen, omasum, abomasum

what are four compartments of stomach in ruminants?

rumen

largest part of stomach; large fermentation vat with a high population of microorganisms; its role is to provide microorganisms to digest fiber

reticulum

right after esophagus; transfers the ingested food into the rumen or omasum; facilitates the regurgitation of ingesta (substances taken into the body as nourishment; food and drink) for re-mastication (chewing again); if the size of feed particles are long enough, \___ works like a filter and won't allow it to move further so sends it back to oral cavity and get rechewed until it is smaller

omasum

reduce the particle size of digesta; controlling the passage of digesta into the lower tract; absorption of nutrients; second gate, if particles are too long, won't let them move on; work as a filter

abomasum

function is similar to the glandular stomach of non-ruminants

monogastrate

an animal with a single-compartmented stomach, young calves should be treated like these nutritionally bc their stomach hasn't developed yet

two

how many months does it take for sheep and goats to develop their stomach; this is when they are weaned

nine

how many months does it take for cattle to develop their stomach?

four

how many months does it take for elk and deer to develop their stomach?

GI tract

relatively long in ruminants (small intestine: 40m; cecum, 0.7m; colon, 10m in cattle)

wombats

only animals whose poop is a cube; elasticity of intestines helps to shape their distinctive poops; poop on top of rocks to mark their territory; stretch their small intestine four times than usual, requires a lot of energy but it is worth it to them

digestive enzymes

food is mixed with these before microbial digestion in the cecum and large gut in non-ruminants; in ruminants, they attack food after initial microbial fermentation in rumen

pre gastric fermenters

occurs in the rumen of ruminant animals; do microbial digestion first

microbial digestion

the natural processes by which micro‐organisms break down and use a substance; occurs in the digestive organs that follow the small intestine: the large intestine and cecum

monogastrics

hind gut fermenters that do enzymatic digestion first; single-compartmented stomach

enzymatic digestion

the break down of food by enzymes for absorption

amylolytic, lipolytic, proteolytic

what are the major classes of digestive enzymes?

saliva, glandular stomach, abomasum, proventriculus, pancreas, and duodenum

digestive enzymes are found in: