Question: how are cows able to digest grass?
Answer: 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.