Because the animals push the load with their foreheads, there are several factors that affect draft. One of the most important is that the steers need to have short thick necks so that there is less tendency for the neck to curve or sway. This is why the preferred breeds for oxen in Nova Scotia are Hereford crosses, most often Hereford x Durham. The angle of draft is controlled by a pole, or wooden tug, that is attached to the yoke with two adjustable lengths of chain. The angle with which the tug meets the yoke can be adjusted so that when the steers push into the load, the draft neither forces their heads up too high nor down too low. Like all draft animals, they need a constant angle of draft that allows them to lift the load.