I was going to say compost. I haven't seen anyone say compost in the other threads like this and I was surprised.
I'm going to start to save mine for my older brother. He puts apples and stuff out for the deer on his property and the grains would be a nice addition.
Judging by the trail cameras that he has in the woods near the apples, the elk and coyotes eat more of the apples than the deer. At least the coyotes probably won't eat the grain.
If you like to feed the birds in your yard, the spent grain would be good for that also.