The origin of bulls and cows dates back 10,000 years. They are said to have originated from a group of wild beasts called Aurochs. Aurochs were up to 2 times the size of modern cows and bulls.
Cows are kept mainly for 2 purposes: milk and breeding. In their first 2 years, female calves are known as heifers. During this period, they do not produce milk or calve.