There are several plants which can be used to make hay and a mostly different list of plants used to make straw. While hay is fed to various animals, straw is used primarily as bedding for livestock. So, let's compare the lists. Hay plants include timothy, fescue, alfalfa, clovers, orchard grass, ryegrass, and sometimes buckwheat. Straw plants include wheat, rye, oats, rice, barley, and several other less often used plants. Animals which eat hay mainly include cattle, horses, goats, and sheep. It should be noted that there are hay mixtures which are more appropriate for certain animals and so it's the case that not all hay mixtures should be considered equivalent.