Horses, Hind-gut fermenters

Question 1

Teeth

Answer 1

incisors are designed to shear grass stems and the cheek teeth are hypsodont, with parallel ridges of enamel that form an effective shewing and grinding surface to shear open fibrous cell walls that protect the cells of the stems and the leaves.

Question 2

large intestine

Answer 2

increased capacity for fiber digestion by expanding the cecum and colon where microbes break down the cellulose into glucose, releasing VFAs. VFAs are very efficiently absorbed along the large intestinal wall. microbes also break down cell walls to gain access to the protein inside but use it for their own growth. free animo acids are released but are poorly absorbed along the gut wall. same with vitamins synthesized by the microbes.

Question 3

mouth, stomach and small intestine

Answer 3

when grain is available, starch, grain and protein can be broken down and absorbed in the upper digestive tract through the action of the animal’s own digestive system. efficient b/c the microbial middle man is avoided. oil is also digested in the small intestine