Why do animals cud?
Cud is the portion of food which returns to the mouth from the stomach so that it can be chewed again. Many ruminant animals show this property so that they can digest the cellulose and hemicellulose present in the food products. When these organisms have food, it goes into an organ called rumen where they have symbiotic microorganisms which degrade the cellulose present in food. This partially digested food again reaches mouth so that it can be digested by the normal digestion process.