Animal Sci Exam 2 - Comparitive Animal Digestion

Front 1

digestion

Back 1

-breakdown of food by the digestive system(tract) in preparation for absorption and utilization by the animal

-breakdown of complex materials into their constituent parts so the nutrients can be absorbed and metabolized in the body

Front 2

types of digestive systems

Back 2

-monogastric: simple stomach (elephant...interesting)

-ruminant (cranial fermenter): multi-compartmented stomach

-hind gut (caudal) fermenter: simple stomach, but very large and complex large intestine

Front 3

monogastric examples

Back 3

chickens

pigs

turkeys

dogs

cats

Front 4

ruminant examples

Back 4

beef cattle

dairy cattle

goats

sheep

deer

Front 5

hind gut fermenter examples

Back 5

horses

rabbits

ostrich

Front 6

monogastric mouth

Back 6

-mechanical breakdown of foodstuffs by chewing (reduces particle size, increases surface area for action of enzymes)

-salia added as a lubricant and, in some species, contrains amylase to begin starch digestion

Front 7

monogastric esophagus

Back 7

-tube connecting the mouth to the stomach

Front 8

monogastric stomach

Back 8

-enzymatic digestion of proteins begins

-foodstuffs reduced to liquid form

Front 9

monogastric liver

Back 9

-center of metabolic activity in the body

-major role in digestive process is to provide bile salts to small intestine (needed for digestion and absorption of fats)

Front 10

monogastric pancreas

Back 10

-provides a potent mixture of digestive enzymes to the small intestine to help in digestion of fats, carbohydrates, and proteins

Front 11

monogastric small intestine

Back 11

-3 sections: duodenum, jejunum, ileum

-site of final stages of chemical enzymatic digestion

-where almost all nutrients are absorbed

Front 12

monogastric large intestine

Back 12

-3 sections: cecum, colon, rectum

-site of water absorption from G.I. tract

-bacterial fermentation occurs (production and absorption of volatile fatty acids) - somewhat limited in monogastrics

-feces formed

Front 13

poultry beak

Back 13

-no lips, no teeth, no chewing

Front 14

poultry crop

Back 14

-out-pocketing of the esophagus that provides storage for consumed food

-foodstuffs moistened and softened (little if any digestion)

Front 15

poultry proventriculus

Back 15

-glandular stomach where first significant amount of digestive juices are added to feed

Front 16

poultry ventriculus (gizzard)

Back 16

-muscular organ used to grind and break up feed

-may contain grit (small stones) eaten by animal

Front 17

poultry cloaca

Back 17

-common chamber into which digestive, urinary, and repro tracts come together

-when fecal material is excreted, the cloaca will fold back at the vent and allow rectal opening of the large intestine to push out, closing the repro tract opening

Front 18

ruminant stomach

Back 18

-structure and function of stomach is the major difference between monogastrics and ruminants

-multi-compartmented stomach: rumen (fermentation vat), reticulum (honeycomb), omasum (many plies), abomasum (true stomach)

Front 19

rumen stomach compartment

Back 19

-large, anaerobic fermentation vat

-houses microorganisms: protozoa (100,000 per gram of rumen fluid)

bacteria/fungi (100 million per gram of rumen fluid)

-lined w/millions of papillae needed for absorption - 'shag carpet'

-saturated w/gases and in constant motion

-contractions occur several times per minute

Front 20

functions of microorganisms in rumen

Back 20

-digest roughages

-synthesize volatile fatty acids (VFA's), microbial protein, and vitamins K and B-complex

Front 21

contractions in rumen

Back 21

-serve to mix contents, aid in eructation of gases, and move fluid and fermented feedstuffs into the omasum and abomasum

Front 22

rumination

Back 22

-ruminants are known for 'cud chewing'

-involves: bolus of previously eaten feed carried back into the mouth by reverse peristalsis, fluid in bolus is squeezed out w/tongue and re-swallowed, bolus is re-chewed and re-swallowed

-may occupy about 1/3 of day

Front 23

eructation

Back 23

-belching

-fermentation of feed in rumen generates enormous quantities of gas: 30-50 liters/hr in adult cattle; 5-7 liters/hr in adult sheep or goats

-belching gets rid of fermentation gases

-bloating can result in death from asphyxiation (can give soapy water, mineral oil, use a trochar!)