Lecture 13 - Digestive Systems Continued

Question 1

What is rumination

Answer 1

The act of regurgitation, re-mastication, re-salivation and re-swallowing

Question 2

What is the abomasum?

Answer 2

“True stomach”
Glandular
-has acidic,enzymatic and mucous secretions

Question 3

What are the characteristics of the reticulum?

Answer 3

• tissues arranged in a network: “Honeycomb”
• traps large particles
• collects metal and hardware
• next to the heart “hardware disease”

Question 4

What are some characteristics of the Rumen?

Answer 4

-not completely separated to the reticulum (reticulo-rumen)
- left side
-largest of the 4 compartments
-primary site for microbial fermentation
-lined with papillae for increased absorption
-storage and “soaking”
-microbial protein production
Microbial fermentation leads to volatile fatty acids and their absorption which is a source of energy for animal
-pH of 6.5
-anaerobic
-temp=101-103 degrees

Question 5

What are the functions of rumen microbes

Answer 5

Synthesize protein, B vitamins, vitamin K, and essential fatty acids

Question 6

What is the importance of VFAs?

Answer 6

Volatile Fatty Acids are short fatty acids

• major source of energy by the animal
• absorbed by rumen wall

Question 7

What is the importance of Conjugated Linoleic Acids (CLA)?

Answer 7

• health benefits: anti-carcinogenic, reduced body fat

- synthesized in the rumen

Question 8

What are the rumen layers?

Answer 8

-uppermost : gas
- middle : recently ingested roughages
- bottom : grain and digested roughages
Dependents on gravity

Question 9

What is eructation?

Answer 9

Elimination of gas produced by microbial fermentation in the rumen

• eructated gas travel up the esophagus
• most of gas is first inspired into the lungs
• expired

Question 10

What is the omasum?

Answer 10

• leaves of tissues :”pages in a book”
• absorption of water and other substances
• leaves “squeeze” water from the feeds
• regulate water volume of digestion into abomasum
• leaves retain particulate matter, fluids move to the abomasum

Question 11

What is the abomasum?

Answer 11

Similar to the nonruminant stomach

• secretion of HCL is relatively greater in ruminants
• reduce pH of alkaline contents coming from rumen

Question 12

In ruminants, carbohydrates that were not fermented in the rumen are fermented where?

Answer 12

Starch : digested by enzymes from small intestine and pancreas

Fiber : pass to large intestine (for hindgut fermentation)

Question 13

What is the esophageal groove?

Answer 13

• milk bypasses rumen via esophageal groove and goes directly to omasum
• grooves contracts and forms a tube which leads to the milk bypassing the rumen and reticulum
• muscular fold on the wall of the reticulum

Question 14

The rumen remains undeveloped if what?

Answer 14

• young ruminant feeds exclusively on milk
• consumption of grain and forage leads to establishment of rumen microbial population
• the end products of fermentation lead to the development of the rumen