alt Hacker NewsCattle, oxen, horses, camels, mules, donkeys, etc. The animals that are capable of heavy labor at or exceeding human level weren't present in the Americas. Llama and alpaca are more useful for fiber and meat than labor. Buffalo might possibly be useful but they are too big, wide-ranging, and aggressive to be easily tamed and bred.
Remember chicken and pigs, too. Not useful for labour, but good sources of high value nutrition, and can be fed of scraps or whatever they find around the house and garden.
In Europe, pigs like eating acorns, which are otherwise fairly useless to humans.