1. The Ruminant Digestive System & Nutrition

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

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

4. Ruminant Digestive Systems
Non-ruminant animals cannot obtain the nutritional value from most plant sources unless the food has been modified (ground, mashed, etc.)

6. Ruminant Digestive Systems
The digestive system of ruminant animals starts with:
Mouth, Teeth, & Tongue
Followed by:
Pharynx & Esophagus
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).
Tongue - covered with finger-like projections (papillae) that contain taste buds.
Pharynx - funnels food into the esophagus, preventing food material from entering the lungs.
Esophagus - food tube that leads from the mouth to the stomach.

7. The Ruminant Stomach Rumination: Ruminants are known for “cud chewing”
Rumination involves:
Bolus of previously eaten feed carried back into the mouth by reverse peristalsis
Fluid in bolus is squeezed out with the tongue and re-swallowed
Bolus is re-chewed and re-swallowed
Ruminant animals grasp mouthfuls of food and swallow it before it is chewed.
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.
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.
Rumination may occupy about 1/3 of a ruminant’s day

8. 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.

9. Ruminant Digestive Systems
At this point, ruminant animals have a multi-chambered “stomach”
Rumen – the organ that allows for bacterial and chemical breakdown of fiber to gain the proteins and energy from plant sources.
Pouch for collection and separation
Contains microorganisms (like the rumen)
Provides additional area for fermentation
As fermentation by microorganisms proceed and feedstuffs are digested, smaller and more dense material is pushed into the reticulum = particle separation
Lining has a honeycomb structure
Catches and holds hardware consumed by animal.
“Hardware Disease”
Hardware can be collected and removed with a rumen magnet

10. Ruminant Digestive Systems
The rumen has a very thick, muscular wall.
It fills most of the left-side of the abdomen
In cattle the rumen can have a capacity of up to gallons!
Normal gallons
Large, anaerobic fermentation vat
Houses microorganisms
Functions of microorganisms
Digest roughages
Synthesize Volatile Fatty Acids (VFA’s), microbial protein, and vitamins K and B-complex
VFA’s absorbed in rumen
Lined with millions of papillae (short projections on wall of rumen) needed for absorption
“Shag carpet” appearance
Rumen saturated with gases and in constant motion
Contractions occur several times per minute
Serve to mix contents, aid in eructation of gases, and move fluid and fermented feedstuffs into the omasum

11. 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.

12. Papillae in Rumen

13. Papillae in Rumen

14. Ruminant Digestive Systems
Next the feed moves into:
Reticulum - honeycomb-like interior surface, this part helps to remove foreign matter from the food material.
Pouch for collection and separation
Contains microorganisms (like the rumen)
Provides additional area for fermentation
As fermentation by microorganisms proceed and feedstuffs are digested, smaller and more dense material is pushed into the reticulum = particle separation
Lining has a honeycomb structure
Catches and holds hardware consumed by animal.
“Hardware Disease”
Hardware can be collected and removed with a rumen magnet

15. Reticulum - full

16. Reticulum - cleaned

17. Tripe = Delicious?
People Eat Tripe

18. Ruminant Digestive Systems
Omasum - section that is round and muscular.
“Grinds” the food material and prepares the food material for chemical breakdown.
A heavy, hard organ with a lining that has many folds (leaves/plies)

19. Omasum - full

21. Ruminant Digestive Systems
Abomasum - The true, glandular stomach 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.).
The true, glandular stomach
Secretes acids and functions very similarly to monogastric stomach
Secretes lysozyme
Enzyme that efficiently breaks down bacterial cell walls
Needed to break down the large quantities of bacteria that pass from the rumen
Rennet used in cheese-making

22. Abomasum – inside view

23. Ruminant Digestive Systems
Followed by:
Small Intestine  Large Intestine  Colon Rectum Anus
Small Intestine - where most of the food material is absorbed into the bloodstream
Large Intestine - begins to prepare unused food material for removal from the body
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.

24. Digestive Tract – Bovine
Liver
Gall bladder
Cecum
Pancreas

25. Digestive Tract – Bovine
Esophagus
Rumen
Omasum
Reticulum
Abomasum
Pancreas
Liver
Gall bladder
Cecum
Small intestine
Large intestine
Rectum

26. Compare the monogastric digestive system with the ruminant system through models (using candy)