An ox is a bull that has been castrated. Oxen are used in some countries for pulling vehicles or carrying things. Domesticated form of large bovid (species Bos taurus) that once moved in herds across North America and Europe (where they have disappeared) and Asia and Africa (where some still exist in the wild). The docile castrated male is used as a draft animal in many countries. Oxen are used for food in some areas. The term is also applied to a castrated male of any cattle breed. See also aurochs, yak