Animal Digestion Chapter #2

What are Nutrients? n parts of food which provide for growth, maintenance, body functions n Carbohydrates (CHO) n Fats n Proteins n Vitamins n Minerals n Water

What is a Ruminant? n Animals with more than one stomach n Chew their cud (re-chew food) n Cows, sheep, goats n Cows have four stomachs n Alf has eight stomachs

Why don’t cattle need as much B vitamins? n Microorganisms in the stomach of the cow make their own B vitamins n Can also make some proteins if given the right kind of Nitrogen

NonRuminants n Foragers: Horse, rabbit n NonForagers: pig, poultry

How much to feed? n Depends on function of animal n Pregnant, Lactating, Working, Growing n How often to feed Depends on stomach size & rate of metabolism Depends on stomach size & rate of metabolism Stomach size is relavant to amount of feed fed Stomach size is relavant to amount of feed fed Mink = 4-6 times/day, Cows = 1-2 /day Mink = 4-6 times/day, Cows = 1-2 /day

What foods give energy? n Carbohydrates (starch & cellulose) & Fats n Fat = 2 1/2 times energy of CHO n Energy is major part of a feed ration n Up to 90% of a ration for a steer n Measured in Kilocalories or TDN (Total Digestible Nutrients)

What are Proteins? n Used to build muscle, body tissue n Made of amino acids n Ruminants can make some proteins n Simple Stomachs need specific amino acids

What are Minerals? n Natural elements which regulate certain body functions n Na, Ca, P, Fe, Cu, K, Mn, Mg, Zn, Mo, Se, I, Co n Most are trace minerals

What are vitamins? n Compounds responsible for certain functions n Fat Soluable = A, D, E, K n Water Soluable = B, C

Feed Additives n Pharmaceutical or nutritional substances that are not natural feedstuffs are added to made-up and stored feeds for various purposes, chiefly to control infectious disease or to promote growth. Improper use may cause poisoning in the subject animals or undesirable residues in food for human consumption produced by the animals.

What are additives for? n Antibiotics: disease prevention n Coccidiostats: control parasites n Xanthophyll: makes egg yolks yellow n Hormones: increase growth n Tranquilizers: calm nerves (cattle, turkeys) n Antioxidants: prevent feed from getting rancid n Pellet Binders: keep in pellet form n Flavoring Agents: make taste better

Livestock Feeding n Roughage = high fiber, low energy n Concentrate = low fiber, high energy

How is a ration balanced? n Pearson square: balance a ration using any two ingredients for one nutrient n How much Soybean Meal (44% Protein) should be mixed with Barley (13% Protein) to get a mixture that is 16% protein?

Pearson Square

n Soybean Meal = 3 parts n Barley = 28 parts n Total Parts = 31 n Soybean Meal = 3/31 or 10% n Barley = 28/31 or 90% n If mixing a ton (2000#) SBM = 200#, Barley = 1800#