because they have four stomachs
Horses have a simple (one) stomach. Most roughage is digested in the large intestine where it is processed into volitile fatty acids through bacterial action.
Roughages are materials that cannot be digested. Another term for roughages is fiber.
meat. things that will poison them, or things that their stomach won't be able to digest. pretty much the same as us.
Fats are digested in the small intestine.
No because it can not digest a rabbit
Horses should not eat this, they can but it is not advised because it is hard for them to digest and can cause colic.
Functional Cecum
Horses have bacteria in their gut that helps digest their food. The bacteria needs time to adjust to new food so you add a little at a time. If you change the food quickly the horse could get stomach ache (colic) as it wont be able to digest the new food. Colic is a serious condition in horses and can be life threatening so best avoided.
Horses chew their hay or grains in their mouth with their teeth so that it is easier for their stomach to digest. Horses chew from side to side as in a motion of a grinder.
Horses are not able to digest marrow. It is not really beneficial to them and can even cause some digestive problems.
It takes the toxins out of the food
Horses defecate to empty their bodies so that they can eat more food and then digest it. If horses didn't defecate then they would have all their waste building up inside them and then become ill
vitamin C, water roughages(fiber) etc