Digestion and Nutrition

Ruminant digestive system

• Mouth- bites and chews food• Rumen- large part of ruminant’s

stomach where bacteria change large amounts of roughages into amino acids

Ruminant digestive system

• Reticulum- the part of the ruminant stomach where liquids go

• Omasum- grinds and squeezes feed and removes 60-70% of the liquid

Ruminant digestive system

• Abomasum- true stomach where liquids go

• Small intestine- partially digested feed is mixed with bile, pancreatic juice, and intestinal juice. Most food nutrients are absorbed from the villi in the small intestine

Ruminant digestive system• Large intestine- main function is to

absorb water and to add mucus to the undigested feed, which is feces

• Esophagus- connects the mouth to the stomach

• A ruminant has a 4 part stomach, but the rumen and reticulum take up about 85% of the capacity

Non-ruminant digestive system

• Mouth• Esophagus• Stomach- enzymes act on feed,

churns and mixes feed• Small intestine

Non-ruminant digestive system

• Liver- produces bile that acts on fats• Large intestine• Anus- end of tract• Non-ruminants cannot eat and digest

as much roughage as ruminants

Poultry digestive system

• Mouth- pecks because poultry have NO teeth

• Esophagus- connects mouth to crop

• Crop- stores feed

Poultry digestive system

• Gizzard- crushes and mixes feed with digestive juices, usually contains grit and gravel to assist in crushing feed particles

• Liver

Poultry digestive system

• Small intestine- mixes juices and most food nutrient absorption occurs

• Large intestine• Vent- anus where both solid wastes

(feces) and liquid wastes (urine) pass out of the body

Groups of nutrients

• Carbohydrates- main energy nutrients• Made up of sugars, starches, cellulose,

and lignin• Found in the greatest quantities in

livestock feed• Chemically composed of carbon,

hydrogen, and oxygen

Groups of nutrients• Fats and oils- 2.25 times the energy

value of carbohydrates • At body temperature, fats are solids

and oils are liquid• They carry the fat-soluble vitamins• Extra carbohydrates are stored as fat• Composed of carbon, hydrogen, and

oxygen

Groups of nutrients

• Proteins- organic compounds made up of amino acids

• Contain carbon, hydrogen, oxygen and nitrogen and sometimes sulfur, phosphorus, and/or iron

Groups of nutrients

• Vitamins- trace organic compounds• All contain carbon• Minerals- inorganic materials or

compounds needed in small amounts, no carbon

Group of nutrients

• Water- makes up 40-80% of an animal’s body

Functions of nutrients

• Carbohydrates- provide energy• Fats and oils- furnish 2.25 times the

energy value of carbs and carry fat soluble vitamins

• Proteins- supply material to build body tissues such as muscles, skin and hair

Functions of nutrients

• Vitamins- help regulate many body functions and are designated by letters: A, B, C, D, E, K

• Minerals: provide material for growth of bones, teeth and body tissue and regulates many of the vital chemical body processes

Functions of nutrients

• Water- helps dissolve other nutrients and carry them to different parts of the body

Sources of nutrients

• Carbohydrates: cereal grains such as corn, wheat, oats, rye, barley, and sorghum

• Fats and Oils: grains and protein concentrates

Sources of nutrients

• Proteins: plant sources include soybean meal, cottonseed meal, alfalfa meal, and animal sources include meat meal, fish meal, dried milk and synthetic nitrogen source of urea

Sources of nutrients

• Vitamins and Minerals: most feed ingredients, pre-mixes are added to feed

• Water: usually supplied separated from other nutrients, liquid form

Specific feed sources

• Carbohydrates: corn is most commonly used in US

• Fats and oils: regular feed ingredients• Proteins: animal sources: fish meal,

meat meal plant sources: soybean meal, cottonseed meal

Specific feed sources• Vitamins and minerals: pre-mix• Water: plumbing, ponds, streams• For ruminants, alfalfa hay provides

some energy and high fiber. Molasses can be added to improve taste (palatability) and reduce feed dust

The end