Rumen

The rumen is the largest stomach compartment in ruminant animals like cows, sheep, and goats. It functions as a fermentation tank, where microbes break down fibrous plant material such as grasses and hay that the animals eat. This process allows the animals to extract nutrients from rough plant fibers that they otherwise couldn't digest. The rumen also produces gases like methane, which the animal expels. Essentially, the rumen enables these animals to thrive on high-fiber diets by hosting microorganisms that turn difficult plant material into usable energy and nutrients.