nutrition

animal nutritionist

formulation and preparation of feed to meet the nutritional needs of animals

digestion

the process by which feedstuffs are broken down in the gastrointestinal tract into absorbable units/compounds

list the linings of body cavities from inner to outer

muscosa (absorptive layer), submucosa, muscularis, serosa

mechanical digestion

mastication (chewing), grinding action of the gizzard (poultry), movement of the GI tract (segmentation & peristalsis)

chemical digestion

gastric acid

enzymatic (luminal and mucosal) digestion

digestive enzymes secreted into the GI tract

digestive microorganisms

bacteria, protozoa, fungi (some yeast), bacteriophages

absorption

the process of moving digested feedstuffs through the gut mucosal wall

regurgitation

partially digested food (cud) is brought back up from the rumen

remastication

the animal chews the cud again to break it down further

resalivation

saliva buffers rumen pH and adds moisture

reswallowing

the cud returns to the rumen for continued fermentation

why is it critical to differentiate between monogastrics, hind-gut fermenters, and ruminants?

• adapt to accommodate certain food supply

• affects metabolism and nutrient requirements

• affects type, rate, and form of nutrient absorption

• categorize animals by GI function opposed to diet type

water constitutes up to __% of animal’s body

60-70%

water is in:

• intracellular fluid

• extracellular fluid

  • intravascular fluid

  • interstitial fluid

  • transcellular fluid

functions of water

• metabolism

• solvent

• medium for transport

• diluent

• lubricant

• component of biological reactions

• thermal regulations

sources of water

external:

• drinking water

• water contained in the feedstuff

internal:

• metabolic water

  • produced by the animal’s metabolism as a byproduct of breaking down food sources

insensible water loss (IWL)

water the body loses through the skin & respiratory tract that is not readily measurable

conditions that increase water loss

• heat/heat stress

• production

• disease

types of water loss

• urine

• feces

• sweat (if glands are present)

• insensible

water requirements depend on

• diet

• environment

• physiological state

major source of carbs:

plants

carbs are the key __ __ for animals

energy source

functions of carbs

• provide energy when oxidized

• stored in the form of glycogen

• provide carbons for synthesis of amino-, nucleic-, & fatty acids

• form structural framework of DNA & RNA

• cell to cell recognition by CHO markers in cell surface

monosaccharide

1 sugar

• glucose

• fructose

• galactose

disaccharide

2 sugar molecule

• sucrose

• lactose

• maltose

oligosaccharides

3-7 sugars

• raffinose

polysaccharides

7+ sugars

• starch

• glycogen

• cellulose

only __ can be absorbed from within the GI tract, all other carbs must be hydrolyzed by __

monosaccharides (simple sugar); digestive enzymes

lipids are relatively __ in water

insoluble

what is the most energy dense class of nutrients

lipids

classification of lipids

• simple lipids (oil, neutral fat, waxes)

• compound lipids (phospholipids, glycolipid)

• derived lipids (fatty acids, glycerol)

• sterols (cholesterol, estrogen)

• terpene (retinoid, terpenoid)

function of lipids

• energy supply

• source of essential fatty acids

• carrier of fat-soluble vitamins (A, D, E, K)

• integral constituents of cell membranes

• carrier of steroid hormones

where is the major site of lipid digestion

upper small intestine

how are lipids digested

lipids are discharged slowly from the stomach and mixed with bile, pancreatic, and intestinal secretions (enzymes)

biles cause

emulsification

emulsification

the process of dispersing one liquid in a second unmixable liquid

where do animals get protein

monogastrics: amino acids from food

ruminants: amino acids from food & rumen microbes

function of protein

• growth and maintenance

• regulation of metabolism

• protection of the body

• transport of nutrients and essential materials

• acid/base balance (pH)

• blood clotting

• vision

• energy supply

protein digestion

monogastrics: enzymes from the stomach, pancreas, and small intestines aid in the process of breaking down the proteins

ruminant: microorganisms make microbial protein (ammonia is absorbed from the rumen and converted to urea by liver)

function of vitamins

required for normal growth and maintenance of life

function of minerals

• essential for proper function

• bone development

• immune function

• muscle function