Why can horses live on hay but humans cant? ?

Horses have different stomachs than we do- we're a whole other species! They're herbivores, and we're omnivores.
What is a smaller dog-like animal?
Horses have bacteria in their cecum (part of the significant intestine) that can digest the cellulose in hay. The equivalent in humans is the appendix, which doesn't do much at all. Humans can't return with any nutrients from hay.
Advice on socializing a chinchilla?
Answers:    um cause we arent horses, horses dont eat meat, we do. just because a horse have the same kind of "bones" we do doesnt connect our species to theirs in any course. we are worlds apart.
How long does it nick winter white's to turn white within winter?   My chinchilla merely ate bread! Is anything gonna come up to her?   TURTLE QUESTION! THANKS=D?   What else should I nurture my kid goat except milk?