Volunteer Murray James explains to visitors at the Weald and Downland Museum how they are training two Sussex heifers (not cows as first written) to yoke up and pull a cart like the working oxen did before tractors were widely used. Apparently oxen were more reliable than horses, and easier to feed.
Ha Ha Ha!
I made a mistake above; they were heifers not cows. Cows were too valuable for milk, and more cows!