Cow

A cow is a large farm animal raised by people for milk, meat, and leather. Cows belong to a group of hoofed mammals called cattle. They live on every continent except Antarctica. There are about 1.5 billion cows in the world today, which is nearly one cow for every five people on Earth.

People first tamed wild cattle about 10,500 years ago in the Middle East. The wild ancestor was a huge animal called the aurochs, which stood taller than a man at the shoulder. Aurochs went extinct in 1627. Every cow alive today comes from those early tamed herds. Over thousands of years, farmers bred cows to be calmer, smaller, and better at making milk or meat.

A full-grown cow weighs between 1,000 and 1,800 pounds, about as much as a small car. Females are called cows. Males are called bulls. Young cattle are called calves. A baby calf can stand up and walk within an hour of being born.

Cows eat only plants. Grass is tough stuff, hard for most animals to digest. Cows solve this problem with a four-chambered stomach. Grass goes into the first chamber, the rumen, where tiny microbes start breaking it down. Later, the cow coughs the half-digested food back up into its mouth and chews it again. This second chewing is called "chewing the cud." After more swallowing and more chambers, the grass finally becomes food the cow can use.

All that digesting creates a lot of gas. Cows burp methane many times a day. Methane is a strong greenhouse gas, and with so many cows on Earth, their burps add up. Scientists are testing new cow feeds, including a kind of red seaweed, to cut down on the methane.

Cows are smarter than many people think. They recognize other cows by face, form close friendships, and get stressed when separated from their favorite pasture-mates. They can also learn simple tasks, like pressing a panel with their nose to get a treat.

Cows matter to many cultures. In Hindu tradition, the cow is sacred and protected. In many parts of India, it is against the law to harm one. In the American West, cattle ranching shaped whole states, and the cowboy became a lasting symbol of the country. On a more everyday level, cows give us milk, butter, cheese, yogurt, ice cream, beef, and leather.

The next time you pour a glass of milk, think about the journey. Grass became cud, cud became milk, and milk traveled from a pasture to your kitchen table.