What’s the point of buying enough hay to last four weeks when you can only store enough grain for two weeks?
A 31-gallon metal trash can holds up to three 50-pound bags and they’re great for dispensing daily rations. Rodents will bore into the plastic ones.
An eight-foot round end tank will hold up to twelve sacks. Cover it with plywood or similar material to keep pests away.
At current prices, you’ll be paying about $100 per AUM to feed your horses—unless you have grazing privileges on public lands, in which case you’ll pay $1.35 per AUM.
Western Horse Watchers Association 
Most drought stricken ranges don’t produce enough quality forage to compare with a sack of grain. 125 acres is the minimum grazing range for one animal. sometimes its not even worth $1.35. The politics behind public land resource management are seldom consistent with Congressional laws. But then neither is Congress.