Deer are ruminant animals which means they have a four chambered stomach similar to cattle. A fascinating characteristic about the ruminant's stomach is that it allows the animal to gather a lot of food at once and then chew and digest it later. The four chambered stomach is needed to process the large amounts of low nutrient food that deer eat in order to get the most benefit possible.Depending on the type and abundance of food, the deer can fill its stomach in about one or two hours of grazin.