Adaptation

Question 1

What does the stomach absorb in ruminants?

Answer 1

VFAs - acetate, propionate, and butyrate

Question 2

Where are VFAs absorbed in hind-gut fermenters, but what is the disadvantage of this?

Answer 2

Colon - microbial protein lost in faeces.

Question 3

What is an advantage of hind gut fermentation?

Answer 3

Can alter gut transit time –> horses more efficient on abundant poor quality forage (can decrease transit time).

Question 4

What is the advantage of fore gut fermentation?

Answer 4

Fore-gut fermentation much more efficient.

Question 5

Briefly describe the 3 ruminant nutritional strategies.

Answer 5

1. Browsers (concentrate selectors, eat hydrolysable carbs)
2. Grazers (grass/roughage eaters)
3. Intermediates (adaptable feeders)

Question 6

What is the oesophageal groove, and which animals have it and why?

Answer 6

• A muscular groove in young ruminants (calves, lambs, kids) that directs milk from the oesophagus directly to the abomasum, bypassing the rumen.
• Remains present in browser ruminants to allow diet high in hydrolysable carbohydrate to escape fermentation.
• Prevents milk fermentation in the rumen, which would cause spoilage and reduce nutrient availability.

Question 7

Describe salivary enzymes in carnivores and omnivores.

Answer 7

Carnivores - no salivary amylase
Omnivores - high levels of salivary amylase

Question 8

Compare absorption of molecules between carnivores, omnivores, simple-stomached herbivores and ruminant herbivores.

Answer 8

1. Carnivores / Omnivores:
   Monosaccharides / peptides / monoglycerides & fatty acids absorbed in small intestine
2. Simple-stomached herbivores:
   Monosaccharides / peptides absorbed in small intestine
   VFA absorbed in large intestine
3. Ruminant herbivores:
   VFA absorbed in fore-stomach
   Peptides absorbed in small intestine