Ruminant digestion.

The stomach of a ruminant has four chambers.

  • The grass enters the rumen and the reticulum, where symbiotic microorganisms digest the cellulose.
  • The cow periodically regurgitates and rechews the cud, to further break down the fibersn.
  • The cow reswallows the cud, which moves to the omasum, where water is removed.
  • The cud finally passes to the abomasum for digestion of the microorganisms by the cow's own enzymes.