Applied digestive physio of Ru 1: fermentation of carbs in the Rumen

Question 1

Ruminal pH

Answer 1

6.5

Is the optimum for the microbiome and is maintained by the alkaline saliva

Question 2

Sailva

Answer 2

Produce 20L/day

Buffer: pH of 7.2-8.5 and is composed of HCO3 and HPO4

Question 3

Carb metab- what are the 2 types of carbs

Answer 3

Structural: cellulose, hemicellulose and pectin

They are the cell wall

Include: hay and roughages

Non-structural: starch, fructose and sucrose

They are the cell cytoplasm

Include: cereals

Question 4

Ruminal bact

Answer 4

200 types

Produce EC enzymes that convert polysaccharides to pyruvate–

Then pyruvate is converted to VFA’s by IC enzymes

Question 5

What are the VFA’s and quantity produced daily

Answer 5

Acetate, butyrate and propionate

3-4kg daily

Question 6

What is also produced during polysaccharude/sugar metab

Answer 6

ATP

Question 7

VFA metab: fate of acetate

Answer 7

AcCoA to fat and KB’s

Acetate is necessary for milk fat prod

Incr roughage– incr acetate– incr cellulytic bact abd decr amylytic bact

Question 8

VFA metab: fate of propionate

Answer 8

E

GNG– glucose prod

Question 9

VFA metab: fate of Butyrate

Answer 9

E

Ketones— this is the main source of ketones