Forages as hay or pasture make up the significant share of the daily intake of a horse. Horses are natural grass eaters with front teeth suited for biting off the grass. The molars chew and grind bulky feed, such as hay and coarse grains. A mature horse that is not working hard will eat 1.5 to 2 pounds of air-dry feed per 100 pounds of body weight. That would be 15 to 20 pounds of hay daily for a 1,000-pound horse. In Iowa, horses will require about 2 tons of hay per head per year, plus summer pasture. When meeting nutrient requirements, carefully consider forage quality and nutrient content.