Cud Cud Cud is a portion of food that returns from a ruminant's stomach to the mouth to be chewed for the second time. More accurately, it is a bolus of semi-degraded food regurgitated from the reticulorumen of a ruminant. Cud is produced during the physical digestive process of rumination. The idiomatic expression "chewing one's cud" means "meditating" or "pondering"; similar expressions such as "he chewed that over for a bit", or "chew on that!" likely have the same derivation. The alimentary canal of ruminants, such as cattle, goats, sheep, alpacas, and antelope, are unable to produce the enzymes required to
Chewing sensory perception of the food being eaten, controlling when the food is swallowed. Avoiding chewing, by choice or due to medical reasons as tooth loss, is known as a soft diet. Such a diet may lead to inadequate nutrition due to a reduction in fruit and vegetable intake. Chewing also stimulates the hippocampus and is necessary to maintain its normal function. Chewing is largely an adaptation for mammalian herbivory. Carnivores generally chew very little or swallow their food whole or in chunks. This act of gulping food (or medicine pills) without chewing has inspired the English idiom "wolfing it down".