Animal Nutrition Topic 3043 Carbohydrates and Fats Digestion, Absorption and Feed Consumption Anna Blight

Carbohydrates and Fats The primary energy source in feed

Carbohydrates Contains carbon, hydrogen and oxygen Digestion breaks down carbohydrates into simple starches and sugars

Carbohydrates Sugars and starches are a very important source of energy Roughages are an important source for starch in ruminant diets (hays and silage, etc.)

Carbohydrates Monogastrics better utilize concentrates (cereal grains, oil meals, soybean meals, etc) as source of carbs. Concentrates are high in energy Low in fiber Highly digestible

Fats Primary energy source Contains carbon, hydrogen and oxygen Digestion breaks down fat into fatty acids 2.25 times more energy / pound than carbohydrates

Digestion and Absorption The role of digestion is to reduce feed particles to molecules Molecules can be absorbed into the blood and eventually support body functions

Digestion and Absorption Digestibility refers to the amount of various nutrients in a feed, which can be absorbed from the digestive tract Animals are classified as ruminants or monogastrics

Ruminants Cows, goats and sheep Rumination = Chew cud (re-chew a regurgitated bolus of feed)

Ruminants Has a complex stomach consisting of more than one compartment The four compartments are called rumen, reticulum, omasum and abomasom.

Ruminants The rumen is a large fermentation vat where bacteria and protozoa thrive and break down roughages to obtain nutrients for their own use. Animal has mutualistic relationship with microorganisms

Cattle synthesize B vitamins Microorganisms in the gut make B-complex vitamins Can also make some proteins if given correct type of nitrogen Later these microorganisms are digested in the small intestine to provide nutrients for the animal’s use

Fermentation process Microbial fermentation of carbohydrates produces volatile fatty acids as waste products Animal uses volatile fatty acids as major source of energy Also produces large amounts of methane gas and some carbon dioxide

Monagastrics Pigs, horses, poultry and humans Simple stomach, one compartment Enzymes present in saliva and in the stomach aid in digestion

Monagastrics Carbohydrates break down into simple starches and sugars Proteins to amino acids Fat to fatty acids

Monogastrics Cannot significantly synthesize B-complex vitamins or amino acids Small intestine receives finished products of digestion Small intestine is most important area for digestion and absorption of feed