Wild yaks stand about two meters tall at the shoulder. Domestic yaks are about half that height. Both types have long shaggy hair to insulate them from the cold. Wild yaks can be either brown or black. Domesticated ones can also be white.
Domesticated yaks are kept primarily for their milk and meat. They are also used as beasts of burden, transporting goods across mountain passes for local farmers and traders as well as in support of climbing and trekking expeditions. Often the pack animals are actually crossbreeds of the yak and Bos taurus (common domestic cattle). These are known in Tibetan as dzo or dzopkyo.
The wild yak is an endangered species.