Rumen Microbial ecosystem Rumen Esophagus 食道 Small intestine Reticulum 蜂巢胃 Omasum Rumen 重瓣胃 (a) Abomasum 皱胃 Herbivorous mammals that possess a special organ, the rumen are called ruminants. Within rumen, digestion of cellulose and other plant polysaccharides occurs through activities of microorganismsRumen Microbial Ecosystem Herbivorous mammals that possess a special organ, the rumen are called ruminants. Within rumen, digestion of cellulose and other plant polysaccharides occurs through activities of microorganisms 食道 蜂巢胃 重瓣胃 皱胃