1. Daily Food for Thought Trace and name the parts of the monogastric digestive system.

2. Monogastric Digestive System Mouth Esophagus Stomach Duodenum Jejunum Ileum Cecum Colon Rectum Anus

3. Ruminant Digestive Systems Learning Target: I can trace identify the parts of the ruminant digestive system and describe the functions of each.

4. The Ruminant Digestive System

5. Ruminant Digestive Systems Functions of the digestive system of animals include: ingestion (eating) chewing (mastication) swallowing (deglutition) absorption of nutrients elimination of solid wastes (defecation)

6. Ruminant Digestive Systems The digestive system changes food nutrients into compounds that are easily absorbed into the bloodstream.

7. Ruminants 2.8 billion domesticated ruminants Cattle, sheep, deer, elk, bison Pregastric fermentation Ability to chew cud at frequent intervals distinguishes true ruminant from other foregut fermenters Kangaroo, colobine monkey are not true ruminants Four compartment stomach Reticulum Rumen Omasum Abomasum

8. Ruminants vary in size and habitat

9. Ruminant Digestive Systems Different species of animals have digestive systems adapted to the most efficient use of the food they consume. The anatomy and physiology of the digestive systems of herbivores, carnivores, and omnivores all differ.

10. Ruminant Digestive Systems Ruminants are those animals that contain a multi-chambered digestive system (polygastric) that allows the animal to gain the majority of their nutritional needs from forages and other roughages. Forage refers to grasses, roughages refers to other high-fiber food sources.

11. Classification of Ruminants by Feeding Preference Classes of ruminants Concentrate selectors Intermediate feeders Roughage grazers

12. Concentrate Selecting Species Properties Evolved early Small rumens Poorly developed omasums Large livers Limited ability to digest fiber Classes Fruit and forage selectors Very selective feeders Duikers, sunis Tree and shrub browsers Eat highly lignified plant tissues to extract cell solubles Deer, giraffes, kudus

13. Intermediate Feeding Species Properties Seasonally adaptive Feeding preference Prefer browsing Moose, goats, elands Prefer grazing Sheep, impalas

14. Roughage Grazing Species Properties Most recently evolved Larger rumens and longer retention times Less selective Digests fermentable cell wall carbohydrates Classes Fresh grass grazers Buffalo, cattle, gnus Roughage grazers Hartebeests, topis Dry region grazers Camels, antelope, oryxes

16. Ruminant Digestive Systems The length and complexity of the digestive system depends on the species. In herbivores, it is very long and complex.

17. Ruminant Digestive Systems Picture of digestive system of cow Rectum Anus Colon Cecum Small Intestine Rumen Kidney Pancreas LiverEsophagus Pharynx Teeth Tongue Salivary Gland Reticulum Omasum Abomasum

18. Ruminant Digestive Systems The digestive system of ruminant animals includes the : Mouth - grasps the food Teeth - grind the food Ruminants have only one set of teeth in the front of the mouth (incisors), and two sets in the back (molars).

19. Ruminant Digestive Systems Tongue - covered with finger-like projections (papillae) that contain taste buds. Salivary glands - secrete saliva, that moistens food and is mixed with the food material to aid in swallowing.

20. Ruminant Digestive Systems Pharynx - funnels food into the esophagus, preventing food material from entering the lungs. Esophagus - food tube that leads from the mouth to the stomach.

22. Ruminant Stomach Anatomy: Reticulum Rumen Omasum Abomasum

23. Ruminant Digestive Systems At this point, ruminant animals have a multi-chambered “stomach” Reticulum - honeycomb-like interior surface, this part helps to remove foreign matter from the food material.

24. Reticulo- rumen Although structurally they appear as a single continuous compartment, functionally they are distinctly different

25. Reticulum - full

26. Reticulum - cleaned

27. Reticulum Honeycomb lining No secretions Formation of food bolus Regurgitation initiated here Collects hardware (nails, wire)

28. Ruminant Digestive Systems Ruminant animals grasp mouthfuls of food and swallow it before it is chewed. They wrap their tongue around a mouthful of grass, clamp down their teeth, and pull to break the grass at its weakest point, and swallow.

29. Ruminant Digestive Systems Ruminants will“chew their cud” (regurgitate) their food material and then grind it with their molars at a time when the animal is resting. This is done until the food particles are small enough to pass through the reticulum into the rumen.

30. Ruminant Digestive Systems Since ruminant animals do not “chew” their food when it is taken in, at times foreign material like rocks, nails, small pieces of wire, can be swallowed.

31. Ruminant Digestive Systems While the animal is “chewing its cud” foreign particles that are heavy are allowed to “sink” in the reticulum, preventing many foreign particles from entering the rest of the digestive system. Once foreign material enters the reticulum, it stays there for the life of the animal.

32. Ruminant Digestive Systems If enough of this foreign material remains in the reticulum, it may cause damage and infection of the reticulum (hardware disease).

33. Telephone Cord

34. Wire

35. Sponge taken from digestive system of an animal

36. Ruminant Digestive Systems Rumen - the organ that allows for bacterial and chemical breakdown of fiber. The rumen has a very thick, muscular wall. It fills most of the left-side of the abdomen

37. Ruminant Digestive Systems The walls of the rumen contain papillae (that can be up to 1 cm. in length), where the bacteria that are used to breakdown fiber live. In some ruminants (dairy cattle) the rumen can have a capacity of 55-65 gallons!

38. Rumen Digestion and fermentation vat 40-50 gallons No secretions Contains anaerobic microbes (25-50 billion bacteria/mL fluid) Also protozoa, fungi Produce VFA, protein Papillae lining Increase surface area Absorption of VFA Passive diffusion

39. Papillae in Rumen

41. Ruminant Digestive Systems Omasum - section that is round and muscular. “Grinds” the food material and prepares the food material for chemical breakdown.

42. Omasum Laminae/manyply lining Muscular folds No secretions Reduces particle size Absorption of water ~60% removed Absorption of VFAs ~2/3 of VFAs entering or 10% of total produced Prevents buffering of the abomasum

43. Omasum - full

44. Ruminant Digestive Systems Abomasum - very similar to the stomach of non-ruminants. this is where the majority of chemical breakdown of food material occurs. mixes in digestive enzymes (pepsin, rennin, bile, etc.).

45. Abomasum – inside view

46. Ruminant Digestive Systems Small Intestine - where most of the food material is absorbed into the bloodstream Contains three sections: duodenum jejunum ileum

47. Ruminant Digestive Systems The food material is continually squeezed as it is moved through the small intestine, becoming more solid. The majority of the food material absorption occurs in the duodenum and the jejunum.

48. Ruminant Digestive Systems Large Intestine - begins to prepare unused food material for removal from the body a portion of the large intestine in some animals contain pouches that may contain enzymes for further species-specific digestion (horses and rabbits (cecum)).

49. Large Intestine Fermentative digestion Bacteria similar to rumen, but no protozoa Digestion in colon may account for as much as: 27% of cellulose digestion 40% of hemicellulose digestion 10% of starch digestion Only important in conditions that increase the amount of fermentative carbohydrate entering the large intestine Increased rate of passage of forages High grain diets May account for as much as 17% of total VFA absorption VFAs are efficiently absorbed, but primarily used as energy source for large intestinal mucosa cells

50. Absorption of ammonia-N May account for as much as 30 to 40% of the net transport of N into body fluid Absorbed N may be used for: Synthesis of nonessential amino acids Recycling of N to the rumen Important on low protein diets Regulated by: Increased by increasing N concentration of diet Decreased by increasing the amount of carbohydrate fermented in the large intestine Mineral absorption Water absorption 90% of water entering the LI is absorbed Large Intestine

51. Ruminant Digestive Systems Colon - collects the unused food material that is to be removed from the body Rectum - “poop chute” Anus - opening through which the waste is removed. Controlled by sphincter muscles, that also help protect the opening.

52. Ruminant Digestive Systems In conclusion, the rumen allows for bacteria to breakdown fiber, enabling ruminants to gain the proteins and energy from plant sources. Non-ruminant animals cannot obtain the nutritional value from most plant sources unless the food has been modified (ground, mashed, etc.) index

53. Ruminant Digestive Systems Ruminants are those animals that contain a multi-chambered digestive system (_________) that allows the animal to gain the majority of their nutritional needs from _______ and other _____________.

54. Ruminant Digestive Systems At this point, ruminant animals have a multi-chambered “__________” _________ - honeycomb-like interior surface, this part helps to remove foreign matter from the food material.

55. Ruminant Digestive Systems ______ - the organ that allows for bacterial and chemical breakdown of fiber. The _____ has a very thick, muscular wall. It fills most of the _______ of the abdomen

56. Ruminant Digestive Systems _______ - section that is round and muscular. “______” the food material and prepares the food material for chemical breakdown.

57. Ruminant Digestive Systems __________ - very similar to the stomach of non-ruminants. this is where the majority of chemical breakdown of food material occurs. mixes in digestive __________ (pepsin, rennin, bile, etc.).