Our horses get about 1/3 of a square bale of hay per day. they are at pasture permanently, and mine get daily trail riding while the rest get no work at all. I think we are putting out 8 bales a day, and there is something like 25 horses...not sure the exact number. Of course the pushier ones get more than the meek ones, but it all evens out in the end.
Allie