5 Organs of Digestive System MonogastricsMouthMechanical breakdown of foodstuffs by chewingSaliva added as a lubricant and begins digestion.EsophagusTube connecting the mouth to the stomach.
6 Organs of Digestive System MonogastricsStomachEnzymatic digestion of proteins begins.Food reduced to liquid form.LiverCenter of metabolic activity in the body.Provides bile salts to small intestine (needed for digestion and absorption of fats).
7 Organs of Digestive System MonogastricsPancreasProvides digestive enzymes to the small intestine to help in digestion of fats, carbohydrates, and proteins.Small Intestine3 sections – duodenum, jejunum, ileumSite of final stages of chemical enzymatic digestion.Where almost all nutrients are absorbed.
8 Organs of Digestive System MonogastricsLarge Intestine3 sections – cecum, colon, rectumSite of water absorptionFeces formed.
9 Avian Considered monogastric One compartment stomach ChickensConsidered monogastricOne compartment stomachCannot digest grass or haySecretes acid and enzymes that digest foodNeed high energy dietsTurkeys
16 Organs of Digestive System RuminantsMouth, esophagus, liver, pancreas, small intestine, and large intestine have functions similar to monogastrics.StomachMulti-compartmented stomach – rumen, reticulum, omasum, abomasum.
17 Parts of the Ruminant Stomach Rumen:Largest compartment“Fermentation Vat”Digests foragesRumen CapacitySpeciesNormal capacityMaximum capacityCow (1000 lb)25-30 gallons55-60 gallonsEwe (150 lb)3-5 gallons5-10 gallons
18 Parts of the Ruminant Stomach Rumen (continued):Lined with millions of papillae (short projections on wall of rumen) needed for absorption.“Shag carpet” appearance
19 Parts of Ruminant Stomach Reticulum:Contains microorganisms (like the rumen).Catches non-digested material.“The Honeycomb”Catches and holds hardware consumed by animal.Hardware can be removed with rumen magnet.
20 Parts of Ruminant Stomach Omasum:“The Book”A heavy, hard organ with a lining that has many foldsFunction not well understood.Filters large particles back to reticulumAbsorbs water
21 Organs of Digestive System MonogastricsAbomasum:“True Stomach”Similar to monogastric or human stomachDigests grains and breaks down proteins
22 Hind-gut Fermenters One simple, glandular stomach Hind-gut fermenter (Cecum) digests plant fiberMust graze oftenMust have fiber (grass or hay)OstrichHorsesRabbits
24 Organs of Digestive System Hind-Gut FermentorsMouth, esophagus, stomach, liver, pancreas, and small intestine have similar functions as compared to monogastrics.CecumLarge and complex compared to monogastrics and ruminants.Cecum similar to rumen in ruminantsFermentation vatMicrobes to break down fiber