Livestock play an important role in most small scale farming systems throughout the world. They provide traction to plow fields, manure which maintains crop productivity, and nutritious food products for human consumption. In most small scale farming systems livestock graze in pastures or woodlands feeding on grass and other herbaceous plants. During the wet season these lands provide adequate forage to maintain productive animals. In the dry season however, the quantity and quality of forage greatly decreases and is generally low in nutritional value.