Most of our horses get just hay, no grain (other than as a treat once in awhile). A group of 10 geldings (all B sized, 34-37") gets a 1200 lb round bale of grass hay ($40) and that lasts them about 8 days. So--that is about 15 lbs of hay per day; a small amount of that is wastage but the geldings aren't too messy or wasteful. A group of 9 mares will go through that same bale in the same 8 days, but they have more wastage--dirty things! They also have a choice of mineral block or salt block. At one time they ignored the salt & devoured the mineral, now it is the other way around. Mineral blocks were sitting unused and salt blocks get devoured.
A group of 5 geldings will go through an 800 lb round bale in 12 days--those are mixed bales--cost $40 once delivery is added in to those. I just got a load of rounds from this particular supplier--price is the same, $40 delivered, but the bales are smaller than last year (which the guy forgot to mention when he told me the price wouldn't be going up from last year)--I'm very disappointed, because these bales are so much smaller. That same group of 5 geldings went through a new bale in just 6 days.
I'm buying small squares (55 lbs) of mixed hay; one hay feeds 7 horses for one feeding, so each gets approx. 7-8 lbs of hay per feed and all clean that up by next feed. Those are $3 each.
I have two young stallions and the mature Mini stallion on grain--also one weanling filly. The two young pony stallions get one litre of grain (1/2 rolled oats, 1/2 Frontrunner Phase Two pellets) twice a day. The Mini stallion gets a 500 ml scoop of rolled oats 2x a day and the weanling filly (Mini) gets 1 litre of grain (half oats, half Phase 2 pellets) once a day. The phase 2 pellets are a mare/yearling feed, 14% protein. I would have been buying the Phase one which is the foal feed, 16% protein, but the yearling pony stallion won't eat it--the Phase Two is the only thing that he will eat--it took time to get him worked up to half oats, initially he would eat the pellets ONLY.
Pellets are, I think, $16 or $17 for a 55 lb bag; rolled oats vary a bit in price, I was paying $7.70 for a 50 lb bag but I picked some up yesterday and it had jumped to $8.60 per bag.
Everyone gets mineral and salt blocks--at the moment salt blocks are the only ones being used.