Hay is cut and dried grass, alfalfa, clover, or other plants. It’s fed to livestock such as cattle, sheep, and horses in lieu of grazing in a pasture.
Straw is the leftover hollow stalks of threshed grain from cereal crops such as wheat, oats, barley, rice, and rye. As animal fodder, straw has less nutritional value than hay, and is only used to supplement the diet. Straw can also be used to make bedding, thatching, baskets, mulch, biofuel, and construction materials.