We have a lot of Coyote in our area.
Generally speaking Coyotes won't bother anything that is bigger than they are, unless it's in a weakened state ---- and they are very good at picking up on the fact that a cow or horse is sick.
However, newborn calves and foals are at high risk.
My neighbor told of a cow in the middle of calving with two coyotes standing withing a few hundred feet of either end of her, just waiting for the calf to be born so they could take ownership of it.
Guess who got shot?-----------------it wasn't the cow or the calf