Have you ever noticed that when you see a cow it always seems to be chewing something? The reason is that cows must chew their food twice in order to digest it properly.
Cows spend nearly eight hours out of every day chewing their cud. This plus normal chewing of food can total upwards of 40,000 jaw movements per day.
Cattle are ruminant animals, this means their stomach contains four compartments:
When a cow first takes a bite, it chews just enough to moisten the food. Once swallowed, the food goes into the first section, the rumen, where it mixes with other acidic digestive liquids and is softened. The softened food is called cud, small balls of food.
Next, the rumen muscles send the cud back up to the cow’s mouth, where it is re-chewed and swallowed again, this time going to the Omasum section of the stomach in order to squeeze out all of the moisture.
Finally, the food enters the last part, Abomasum of the stomach where it mixes with digestive juices and makes its way to the intestine to be completely digested.
Cud chewing is often used as an indicator of a healthy and comfortable herd. A happy, healthy animal will produce more milk or have a higher production of muscle.
Animals who do not chew their cud properly may be scared or have digestive issues such as twisted stomachs or a displaced abomasum, their fourth section of the stomach. Feeding high-quality forages will help to ensure the cows are digesting and chewing their cud properly.
Since cattle are “flight” animals meaning they run from danger, they don’t fight back; it is thought that the original reason for the double digestion was to let the animal eat as much as they could before needing to flee the area. Then they would bring the forage back up to properly digest it at a later, safer time. Cud chewing is also necessary because the foods ruminant animals eat are difficult to digest and it takes extra effort to get all of the nutrients from the food.
Other examples of ruminant animals include deer, camels, buffalo, goats, sheep, and giraffes.