Ox is a common name for a variety of cattlelike mammals, including bison, musk oxen, water buffalo, and yaks. Many different kinds of animals may be called oxen, but only domestic cattle are true oxen.
In the strictest sense, oxen are domestic cattle trained to work for people. These powerful work animals serve as beasts of burden in some parts of the world. Oxen are generally male cattle that work in pairs to pull a cart or load. These males are usually castrated—that is, their sex glands are removed. Oxen have horns that help hold in place the yoke (harness) that enables them to pull loads. Although the term ox refers to males, female cattle also can be used as working cattle.
