Did you have to pick them to keep the horses from eating them?
Maybe there's some sort of relish or applesauce you can make with the green apples.
Yeah - They'll eat way too much at a time, and they can die from colic... They're like rats in that they can't throw up, if they eat something they shouldn't, it has to go all the way through, and they can founder, colic and even die from too much of something.