livestock nutrition

Classes of nutrients

Water, carbohydrates, fats, proteins, minerals, vitamins.

Water

Most important

Carbohydrates and fats

Energy

Proteins, minerals, vitamins

Can provide some energy

Components of a feed

Protein is energy consuming. Fat stores energy (dense).

Energy partitioning by a cow

Basal metabolism, activity, growth, basic energy reserve, pregnancy, lactation, additional energy reserve, estrous cycle and pregnancy initiation, excess energy reserve

Digestive tracts of a pig

Limited capacity, chemical secretions and enzymes critical for digestion. Limited microbial action, limited fiber digestion

4 stomach

Ruminant animals

4 compartments

ruminant animals

Poultry digestive tract

Monogastrics

Eat what? Corn, soybean meal, KEY (easily digested). What does pig feed look like? Ground up, already broken down

Dental

Cattle only have teeth on the bottom

Ruminate digestive tract

Reverse alphabetical order

Ruminant digestive tract

Fiber digestion focused, not 4 stomachs, fermentation of food by microbes

Volatile fatty acids produced

Acetate, propionate, and butyrate,

Rumination

Regurgitation of forage blouses from rumen and reticulum

Eructation

Belching of gases produced by bloat

1rst Rumen (and rumen papillae)

Very large and filled with wet feeds. Site of fermentation. Release of volatile fatty acids.

4th Abomasum (“true” stomach)

Final compartment that is acidic, and has enzymes to digest feedstuffs and breaks down protein into amino acids that can be absorbed in small intestine

2nd Reticulum ( honeycomb)

Small. Traps large feed particles leaving rumen and allows for regurgitation, re chewing, adding saliva, site where ingest metal pieces are trapped and can cause hardware disease

3rd Omasum (water regulation)

Acts like a filter and a valve, uses its lots of folds to squeeze water out of feed so it stays in the rumen

Ruminates

Are meant to eat grass, partners with microbes, microbes digest “tough stuff” (plant cells), animal digest microbes