Animal Nutrition Study 1

Nutrition

Series of chemical, biochemical, and physiological processes that transform food elements into body tissues and activities

Nutrient

Any chemical substance that can be used and is necessary for the maintenance, production, and health of animals

Digestion

Combination of mechanical, chemical, and enzymatic processes in the GI tract that prepares ingested material for absorption by reducing particle size and increasing solubility

Absorption

the passage or movement of the end products of digestion (nutrients) through the wall of the GI tract to the general circulation (blood)

Distribution

movement of nutrients from absorptive sites to various body cells via the bloodstream

Metabolism

Sum of all physical and chemical processes by which living substance is produced and maintained

Anabolism

Constructive process by which simple substances are converted into more complex compounds

Catabolism

Destructive process by which complex substances are converted into simpler compounds

Excretion

the removal of unusable materials and waste products of metabolism from the body

Feedstuff

Any material of natural or synthetic origin fed to animals to sustain them

Diet

Combination of feedstuffs used to supply nourishment to an animal

Ration

Amount of a diet consumed by an animal in a 24-hour period

Supplement

Feed or feed mixture used with another feed to improve nutritive balance and animal performance

Concentrate

Feedstuff high in energy and containing less than 18 percent crude fiber

Roughage

Feedstuff containing more than 18 percent crude fiber

Protein

Amino acids linked together by peptide bonds containing approximately 16 percent nitrogen

Carbohydrates

Nutrients consisting of simple sugars, starch, and fiber

Lipids

Fats composed of a glycerol backbone and three fatty acids; most concentrated form of energy

Fat-soluble vitamins

Vitamins A, D, E, and K

Water-soluble vitamins

B-complex vitamins and vitamin C

Minerals

Inorganic elements required for normal physiological function

Water

Essential nutrient and major component of all body tissues

Oxygen

Not really a dietary nutrient but required for metabolism

Proximate Analysis

System used to evaluate the nutritive content of feeds

Moisture

Portion of feed lost when heated to 100 degrees Celsius

Ash

minerals remaining after muffle furnace at 400 to 600 degrees C

Kjeldahl Method

used to estimate protein content by multiply nitrogen and by 6.25

Ether Extract

feed that represents fat content

Crude Fiber

Feed fraction estimated by acid and base hydrolysis and considered largely indigestible

Nitrogen-Free Extract

Readily available carbohydrates calculated by difference

Stem

Structural part of plant; contains cellulose and lignin; high in carbohydrates

Leaves

Photosynthetic part of plant; high in enzymes and protein

Seeds

Germination and reproduction site; storage of protein and energy

Cereal Grains

Store energy as carbohydrates; examples: corn, wheat, barley

Oil-bearing Seeds

Store energy as lipids; examples: soybean, cottonseed, peanut

Water in body

Essential component of every cell

Fat in body

Found in cell membranes; adipose tissue is energy storage site

Protein in body

Present in every cell; in enzymes, membranes, muscles, skin, tendons

Minerals in bones and teeth

Ca, P, Mg

Minerals in tissues

S, P

Minerals in body fluids

Na, K, Cl

Minerals in blood

Fe (hemoglobin)

Carbohydrates in animals

Hydrolytic Digestion

Digestion using enzymes secreted by the animal tissues; occurs in stomach, small intestine, pancreas

Fermentive Digestion

digestion using microbial enzymes; occurs in rumen or cecum; herbivores

Monogastric

Single-chambered stomach animal

Ruminant

Multi-compartment stomach animal; relies on microbial fermentation

Volatile Fatty Acids (VFAs)

Short-chain fatty acids produced by microbial fermentation; main energy source for ruminants

Mouth

Food acquisition, mechanical breakdown, saliva adds moisture, buffer, and amylase

Esophagus

Transportation of ingesta

Stomach

HCl secretion by parietal cells; pepsinogen by chief cells; protein digestion

Small Intestine

Enzymes from SI and pancreas digest carbs, proteins, and fats; minerals and vitamins absorbed

Large Intestine

Absorbs water, minor minerals, and water-soluble vitamins

Mouth

Food acquisition (tongue important); mechanical breakdown; saliva adds moisture and bicarbonate buffer

Rumen

Microbial fermentation of starch and cellulose; VFAs absorbed; microbial protein formed

Omasum

Water absorption

Abomasum

True stomach; secretes HCl and pepsinogen

Small Intestine

Absorption of digested carbs, fats, proteins, minerals, vitamins

Large Intestine

Water absorption; minor minerals and water-soluble vitamins

Esophageal Groove

Muscular structure in young ruminants; directs milk to abomasum

Regurgitation

Casting up digested feed to mouth

Ruminate

Regurgitate, chew, reswallow

Eructation

Elimination of gas via belching

Bloat

Inability to expel gas

Cecum

Blind pouch off large intestine; site of microbial fermentation

CP & Starch in LI

Already digested and absorbed

Cellulose in LI

Partially fermented to VFAs; some absorbed

B vitamins in cecum

Synthesized but not absorbed

Mouth (poultry)

Food acquisition, no teeth

Crop

In poultry, holding and moistening; minor fermentation

Proventriculus

Secretes HCl and pepsinogen; rapid passage

Ventriculus (Gizzard)

Muscular grinding; contains grit; no enzymes but HCl/pepsin act

Small Intestine

Pancreatic enzymes digest CHO, fats, proteins

Ceca

Two cecums; limited fermentation

Large Intestine

Water absorption; minor minerals and vitamins

Vent

Feces and uric acid excreted together

Enzyme

Protein catalyst that speeds up biological reactions without being consumed

Zymogen

Inactive enzyme form that must be activated to work

Cofactor

Mineral required for enzyme activity

Coenzyme

Vitamin required for enzyme activity

Pepsinogen

Inactive enzyme secreted by chief cells; activated by HCl to pepsin

Pepsin

Active stomach enzyme that breaks down protein into peptides

Rennin (chymosin)

Enzyme in young ruminants that coagulates milk protein (casein)

Salivary Amylase

Enzyme in saliva that begins starch digestion

Lipase

Enzyme that breaks down fats into glycerol and fatty acids

Trypsinogen

Inactive enzyme secreted by pancreas; activated by enterokinase

Trypsin

Active enzyme that breaks down proteins into peptides and activates chymoptrypsin and carboxypeptides

Chymotrypsinogen

Inactive enzyme secreted by pancreas; activated to chymotrypsin

Chymotrypsin

Active enzyme that breaks down proteins into peptides

Carboxypeptidase

Enzyme that removes amino acids from the carboxyl end of proteins

Maltase

Enzyme that converts maltose into 2 glucose molecules

Sucrase

Enzyme that converts sucrose into glucose and fructose

Lactase

Enzyme that converts lactose into glucose and galactose

Nucleotidase

Enzyme that breaks down nucleotides

Nucleosidase

Enzyme that breaks down nucleosides

Alkaline Phosphatase

Enzyme that releases phosphate from organic compounds

Enterokinase

Enzyme in small intestine that activates trypsinogen to trypsin

Gastrin

Hormone secreted by G-cells in stomach; stimulates parietal cells to secrete HCl

Secretin

Hormone released in response to acid in duodenum; stimulates pancreas to secrete fluid and bicarbonate

Cholecystokinin (CCK)

Hormone secreted when fats/proteins enter small intestine; stimulates pancreatic enzyme release and bile secretion