According to Oregon State University Extension Service, an acre may yield between 65 to 165 small bales of hay per cutting, with up to three cuttings per year. The yield depends on location, fertilization, plant species, plant age, moisture content and how tightly the bales are packed.
Horses, cattle, sheep, goats, rabbits and guinea pigs eat hay to supplement or take the place of natural grazing. As of 2014, Florida horses consume 700,000 tons or roughly 25 million small bales of hay each year, according to Ranch Cattle Research.
Hay fields often include alfalfa, clovers, ryegrass, orchard grass, fescue, brome, timothy and/or Bermuda grass. The most nutritious hay has full leaves and unripe seed heads.