Definition:
A digestive process in which plant materials are fermented in a specialized combination of stomach compartments together called the reticulorumen. In ruminants, the fermented cud of the reticulorumen is regurgitated and chewed again to further break down the plant material, a process called rumination. After rumination, the food is finally digested in other stomach compartments, the omasum and abomsum (true stomach). Foregut fermentation also exists in some species that do not ruminate, such as leaf monkeys.
