By Marci Glover Hay consists mainly of dried grass, but there are other plants that grow in the grass. These include alfalfa hay which consists of dried alfalfa used by hay suppliers Plainview. Hay is treated as food for animals during winter or in dry periods when there is little grass growth. Previously, it was fed to cattle on farms, but now silage is also fed to horses, sheep and goats, or in zoos. Hay is made by mowing a meadow and grass clippings and left to dry in the sun for some time....