瘤胃，是反刍动物的第一个胃，一般也是最大的一个胃。在这个胃内寄生着大量的微生物，食物进入瘤胃后在微生物的作用下得以被分解。

• 蜂巢胃
• 重瓣胃
• 皱胃

The rumen, also known as a paunch, forms the larger part of the reticulorumen, which is the first chamber in the alimentary canal of ruminant animals. It serves as the primary site for microbial fermentation of ingested feed. The smaller part of the reticulorumen is the reticulum, which is fully continuous with the rumen, but differs from it with regard to the texture of its lining.