Oxen are bovines trained to do what?

An ox is just a cow – one that has been trained to work as a draft animal. Oxen are usually male cattle. They go through extensive training starting when they are very young to teach them how to pull heavy loads and listen to their human handlers – called drovers or teamsters. They don’t earn the title of “ox” until they have been through four years of this training. Until then, the calves are often called “working steers”. When they are a few months old, the calves are taught to wear their first yoke. The yoke is the piece of wood that goes across their necks and is traditionally held on with bent pieces of wood called bows. The first yoke is very small, and a team may go through a dozen or more incrementally larger yokes until they are fully grown. Besides walking alongside their teamster and wearing a yoke, the calves must learn some commands.

Source: Living History Farms