If you've ever seen a cow lying in the shade with her jaws moving like she's got a mouth full of bubble gum, you've witnessed one of the most important tasks in her digestion. When a cow grazes, she chews her food only a few times before it passes down to the first chamber in her four-chambered stomach -- known as the rumen -- only to return to her mouth later in a fist-sized cud.
The cud that returns to her mouth has been partially digested by bacteria in the rumen, with the digested bits passing along her digestive system. The undigested cud must be broken down by her teeth some more and swallowed again for further processing. The cycle repeats until the entire cud is broken down and digested. The cow will spend approximately eight hours per day chewing her cud if she is healthy and receiving proper nutrition.
A cow that does not chew her cud for at least six hours per day is not receiving enough fiber in her diet. The rumen requires enough fiber to keep the digestive process active for 24 hours each day. Cows fed too much grain or those allowed to go hours without food will spend less time chewing cud. Failure to correct the diet will lead to decreased milk production and eventual health problems.
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