The pig has a digestive system which is classified as monogastric or nonruminant. Humans also have this type of digestive system. They have one stomach (mono=one, gastric=stomach). The monogastric differs from that of a polygastric or ruminant digestive system found in cattle and sheep. These animals have one stomach broken into four compartments. Due to the differences in the digestive systems, cattle can utilize different types of feeds than pigs. Cattle and sheep can live on hay and pasture, while pigs must eat grains that can be digested more easily.