Ruminant digestion pt 2 Flashcards
Growth of the ruminal papillae is stimulated by what?
- Mechanical stimulation (scratch factor effect)
2. Chemical stimulation (VFA)
What is different about grain fed cattles papillae?
There are less and they have abnormal irregular shapes due to lack of mechanical stimulation. So there is less absorption and metabolism and can lead to ruminal acidosis
What are the functions of the ruminal epithelium?
- Absorption of fermentation products
- Metabolism of fermentation products
- Protective barrier
What is the importance of the omasum?
- Acts as pump
- No digestion
- Absorption: water, VFA, bicarb
- Not indispensable
What does the abomasum do?
Secrete gastric juice and regulate flow contents into the duodenum
What is abomasal displacement?
Displaced to the left or right or rumen. See in dairy cows a lot that have given birth. Fills with gas
How do you fix abomasal displacement?
Roll her on her back and suture to the body wall
What is the optimum pH for microbes?
6.8
What makes the rumen suited for microbial habitat?
- Water environment
- Constant temp and pH
- Substrate provided almost continuously
- Ruminal contractions help to mix
- Fermentation products removed by absorption, eructation and passage out of rumen
- No humoral defense mechanisms against
What limits rumen microbial habitat?
- Type of diet
2. Pack of oxygen (only anaerobic metabolsim)
What is most of the microorganisms in the rumen?
Bacteria (gram negative)
When would you not see protozoa in the rumen?
Feed-lot cattle
What do we know about bacteriophages?
Not much
What is the predominant ruminal bacteria and what are its products?
Saccharolytic bacteria; Acids: actetate, propionic, and butyric, gases: CO2 and methane
