Rumination or cud-chewing is the process by which the cow regurgitates previously consumed feed and chews it further. ... This physical process improves digestion rate allowing for higher levels of feed intake, thus greater nutrient input.

Why do cows do rumination?

Cows are known as “ruminants” because the largest pouch of the stomach is called the rumen. ... This process of swallowing, “un-swallowing”, re-chewing, and re-swallowing is called “rumination,” or more commonly, “chewing the cud.” Rumination enables cows to chew grass more completely, which improves digestion.

What does it mean when a cow chews its cud?

According to dairy cow nutritionist Mary Beth de Ondarza, when a cow is chewing her cud, that's a good sign. ... This softened food is called the cud, and it is sent back up to the cow's mouth, where it is re-chewed before going back down into her stomach to be fully digested.