“The cud is then reswallowed and further digested by specialized microorganisms that live in the rumen.”

“When calves are fed milk it is funnelled through the oesophageal groove to the true stomach, bypassing the rumen.”

“Energy from the grain apparently helps complete the conversion of nitrate to bacterial protein in the rumen.”

“So mammals are unable to digest cellulose, except some ruminants that have cellulase-secreting bacteria in their rumens.”

“Unlike human stomachs, rumens contain symbiotic bacteria that enable grazing animals such as sheep, goats, deer, and cattle to digest grass and other fibrous plant matter.”