Ox

We considered entering Oxen with Cows, but they are different enough (although closely related) that we feel they deserve their own entry.

Although some Ox are bred for meat, you are far more likely to encounter them as determined beasts of burden, and they are much valued for their massive strength when carrying or pulling goods.

Long distance merchant caravans almost always use oxen to pull their wagons, unless there is a specific environmental factor making a different animal a significantly better option (which there rarely is).