An ox (plural oxen), also known as a bullock in Australia and India, is a bovine trained as a draft animal. Oxen are commonly castrated adult male cattle; castration makes the animals easier to control. Cows (adult females) or bulls (intact males) may also be used in some areas.
Oxen are used for plowing, for transport (pulling carts, hauling wagons and even riding), for threshing grain by trampling, and for powering machines that grind grain or supply irrigation among other purposes. Oxen may be also used to skid logs in forests, particularly in low-impact, select-cut logging.
Oxen are usually yoked in pairs. Light work such as carting household items on good roads might require just one pair, while for heavier work, further pairs would be added as necessary. A team used for a heavy load over difficult ground might exceed nine or ten pairs.
Oxen are thought to have first been harnessed and put to work around 4000 BC.
Working oxen are taught to respond to the signals of the teamster, bullocky or ox-driver. These signals are given by verbal command and body language, reinforced by a goad, whip or a long pole (which also serves as a measure of length: see rod). In pre-industrial times, most teamsters were known for their loud voices and forthright language.
Verbal commands for draft animals vary widely throughout the world. In North America, the most common commands are:
In the New England tradition, young castrated cattle selected for draft are known as working steers and are painstakingly trained from a young age. Their teamster makes or buys as many as a dozen yokes of different sizes for each animal as it grows. The steers are normally considered fully trained at the age of four and only then become known as oxen.