This animal is a close relative of the Aurochs, the extinct wild cattle of Europe and Asia that was the ancestor of domesticated cattle. The domestic yak is much smaller than its wild ancestors. It is thought to have first been domesticated around 1000 B.C. The coat color can be white, black, brown, yellow, gray, reddish or piebald (Pinto). Because the yak makes grunting sounds, it is referred to as the grunting ox.
It easily carries loads of over 300 pounds on the steepest mountain trails, and in its homelands is also used as a mount. Each animal yields about 7 pounds of coarse wool per year, and the milk, though low in quantity, is quite rich, containing up to 8% butterfat, twice that of a dairy cow! When crossed with domestic cattle, the hybrid offspring is called a Dzo.