What is Yak ?
Yaks belong to the genus Bos, and are therefore closely related to cattle, Yaks have short, thick legs, humped shoulders, large horns, and a thick coat that hangs down to the ankles. Wild yaks were formerly found from Kashmir to West China, but were so extensively hunted for meat and hides that they now survive only in isolated highlands at elevations above 14,000 ft (4,300 m). The English word "yak" derives from the Tibetan in Tibetan this refers only to the male of the species,
the female being called a dri or nak. In English, as in most other languages which have borrowed the word,
"yak" is usually used for both sexes.

Yaks have been domesticated for thousands of years, mostly for the milk, fibre and meat. Their dried dung is used as fuel used all over Tibet, often only fuel available on the high treeless Tibetan plateaus. Yaks transport goods across mountain passes for local farmers and traders as well as for climbing and trekking expeditions. "Only one thing makes it hard to use yaks for long journeys in barren regions. They will not eat grain, which could be carried on the journey. They will starve unless they can be brought to a place where there is grass