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
Kosher animals that naturally live in Canaan, except for primates, and equids (horses, zebras, etc.), which are not mentioned in Leviticus as being either ritually clean or unclean, despite their importance in warfare and society, and their mention elsewhere in Leviticus. In an attempt to help identify animals of ambiguous appearance, the Talmud, in a similar manner to Aristotle's earlier "Historia Animalium", argued that animals without upper teeth would always chew the cud and have split hoofs (thus being ritually clean), and that no animal with upper teeth would do so; the Talmud makes an exception for the case of the camel