Water buffalo, camels, goats, sheep, horses and reindeer are also milked in some parts of the world. In the U.S., there are many different breeds of cows that are raised for milk. Holsteins are the largest breed and produce the most milk. Jerseys are the smallest, but yield milk that is high in butterfat and protein. Some other dairy breeds are Ayrshire, Guernsey and Brown Swiss.
All cows are female.
A cow is an adult female who has had at least one calf. The male is called a bull. A young animal male or female, is a calf. A heifer is a female animal, who has not yet had a calf. A cow doesn't produce any milk until she has had her first calf, which is when she is about two years old.