Thanks for advices everybody :)
I have two different hays, one is for mare, that one is quite rich, and one for him, it was the fourth cut + it was raining the day before we cut it (and that was in the morning). I'm quite sure it's not as rich as the first one :P
I'll work with him more, but he can be only lunged, because his bone is rotated.
I think I'm going to stick with hay and not with pelleted feed, because we own
Fields, and we would have to sell hay if horses wouldn't eat it.
I was thinking about grazing muzzle, actually I was asking for it in the shop last time, but they didn't have it. I'll have to go to other shop, if they have it... That depends on when someone will be able to drive me.