Foregut fermenters

Question 1

Rumen acidosis can be caused by

Answer 1

Not enough saliva acting as a buffer, leading to an increased production of fatty acids in the rumen.
This can be due to high concentrate diets, that decrease the salivary flow

Question 2

Ordina questi strati del rumen dal basso verso l'alto:
liquid layer
gas layer
fiber mat
small particles of high density

Answer 2

small particles of high density
liquid layer
fiber mat
gas layer

Question 3

The reticulum lining is:

a) full of papillae
b) honeycomb shaped

Answer 3

b. this shape helps trapping foreign materials such as stones to prevent puncturing of the digestive tract.

The papillae are located in the rumen and are used to absorb the volatile fatty acids.

Question 4

The function of omasal leaves

Answer 4

Act as a filter, retaining material in the rumen until it has been degraded into small particles

Question 5

The pH in the abomasum is:

a) Extremely acid (1-2)
b) Extremely basic (13-14)

Answer 5

a.

Question 6

Put these in order (and explain their function):

• mouth
• omasum
• reticulum
• rumen
• abomasum

Answer 6

• mouth
• rumen
• reticulum
• omasum
• abomasum

the abomasum is the “real stomach”, as the reticulo-rumen is a fermentation chamber and the omasum is a filter.

Question 7

True or false:
The temperature in the rumen should be at 39°C, the pH should be basic and it should provide aerobic conditions to the microorganisms.

Answer 7

False. It should have ANAEROBIC conditions.

A ph lower than 5.5 is considered a state of acidosis.

Question 8

Which one is the primary source of energy in ruminants?

a. Volatile fatty acids
b. Carbs

Answer 8

a.

Question 9

The end products of the fermentation in the rumen are:

Answer 9

• Volatile fatty acids (VFA)
• Proteins in micro-organism
• Vitamins (B and K vitamin)
• Methane, carbon dioxide, ammonium

Question 10

Function of rumen bacteria

Answer 10

cellulolytic of fibrolytic and amylolytic. cellulase, produced by the bacteria, digests the fiber and produce VFA.

Question 11

Function of rumen protozoa

Answer 11

40% but minor role. digestion of starch and soluble carbohydrates.

Question 12

Function of rumen fungi

Answer 12

break down lignin cellulose complexes and solubilize the lignin

Question 13

Why is non-protein nitrogen important?

Answer 13

In monogastrics NPN is not used, but in ruminants NPN arrives in the rumen and produces ammonia, whuch can become bacterial or microbial protein.

Question 14

The 2 fates of true protein in the rumen

Answer 14

bypass the rumen as undegraded protein

microbial degradation ->production of ammonia -> bacteral protein

Question 15

Where is the bacterial protein digested?

Answer 15

Intestine

Question 16

What is the recycling of urea and when is it necessary?

Answer 16

if the degraded protein is too high and/or the fermentable energy is too low (food is scarce), we can observe an overflow of ammonia in the rumen.
It then flows into the rumen wall and arrives in the liver where is transformed into urea.
urea can be then excreted through urine or can come back in the saliva to reach again the rumen.

Question 17

Difference between concentrate selectors and grazers

Answer 17

Concentrate selectors consume the less lignified parts of herbage including tree and shrub leaves, herbs, fruit etc. Their digestive system is adapted to the use of low fiber forage.
On the contrary, grazers have a feeding and digestive strategy based on the utilization of high fiber, low soluble diets.

Question 18

T or F

Rumen is larger in grazers than in browsers

Answer 18

T

Question 19

Laminitis is usually due to… and results in…

Answer 19

Imbalances in the digestive tract

rotation and retrusion of the third phalanx

Question 20

The kangaroo is a non-ruminant foregut fermenter, and a grazer. They do not cause methane eructations, so what happens to the byproducts of fermentation?

Answer 20

The hydrogen byproduct of fermentation is instead converted into acetate, which is used to provide further energy