Rumen

The rumen, also known as a paunch, is the largest stomach compartment in ruminants and the larger part of the reticulorumen, which is the first chamber in the alimentary canal of ruminant animals.[1] The rumen's microbial favoring environment allows it to serve as the primary site for microbial fermentation of ingested feed.[1] 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. It covers approximately 80% of total ruminant stomach portion

  1. ^ a b "The ruminant digestive system". extension.umn.edu. Retrieved 2021-02-21.