Sheep have four-chambered stomachs like other ruminants, such as cows. This type of stomach is often said to consist of four different stomachs, but is actually one stomach with four different parts. The four parts are the rumen, reticulum, omasum and abomasum.
The rumen is the largest part of the stomach. After the sheep swallows its food, the food ferments in the rumen. The animal regurgitates the contents of the rumen and repeatedly chews it. The fermentation capabilities of the rumen allow animals to survive on fibrous plants that most animals cannot digest. Sheep usually graze on grass, but they occasionally browse on twigs and bushes.