cost to feed a horse monthly
1 Horses also need to feed on grain which costs from $12 and $22 for a 50 pound bag on the average. 2  Daily cost for grain can be placed between $0.75 and $4.80. 3  For instance, daily feed for a horse in North California area, for both hay and grain, will cost around $4 to $8 per day.4  Monthly expenses can run to $130 to $275. Daily cost for grain can be placed between $0.75 and $4.80. 2  For instance, daily feed for a horse in North California area, for both hay and grain, will cost around $4 to $8 per day.