Ruminant Digestion

Question 1

What are the four chambers of a cow’s stomach?

Answer 1

Rumen
Abomasum
Omasum
Reticulum

Question 2

What do the rumen and reticulum do?

Answer 2

They are full of endosymbiotic microorganisms that break down cellulose by fermentation

Question 3

Why do cattle need chambers of their stomach with microorganisms to break down cellulose? Why can’t they do this themselves?

Answer 3

Most herbivores don’t produce cellulases, the enzyme that breaks down cellulose. As cellulose is a core part of their diet, they need a way to consistently break it down.

Question 4

Why do ruminant animals such as cattle regurgitate the contents of the rumen periodically?

Answer 4

So it can be chewed and broken down further (doing this makes them cud chewers)
This increases the surface area of the food to be broken down so the microorganisms can break it down at a faster rate

Question 5

What happens to the food being digested in the omasum?

Answer 5

It is concentrated by water absorption

Question 6

What happens during the digestive process in the abomasum?

Answer 6

The leftover microorganisms are killed by secreted hydrochloric acid
Partially digested by proteases
This is passed on to the small intestine for further digestion and absorption

Question 7

How much protein does a cow derive each day from digestion of its microbiota?

Answer 7

> 100 grams