A group of oxen is referred to as a yoke. Oxen are often used in teams and yoked into a harness to pull heavy loads. Working oxen are normally males that are castrated because steers aren't as aggressive as bulls.
Training begins at an early age, as oxen must learn verbal commands for stop and go, as well as left, right and back up. Oxen are also trained to respond to commands given with a long pole by their master, or teamster. As many as 10 teams of oxen can be yoked to a single wagon if the load is extremely heavy.