Imperial

Imperial and Royal Yaks are not as common as Black and Trim Yaks but are less rare than the Goldens. They hold the position for second largest group of the Yak population. Though Imperial Yaks are also used for meat they hold great value as pets and show animals. The yak, Bos grunniens or Bos mutus, is a long-haired bovine found throughout the Himalayan region of south Central Asia, the Tibetan Plateau and as far north as Mongolia and Russia. In addition to a large domestic population, there is a small, vulnerable wild yak population. In the 1990s, a concerted effort was undertaken to help save the wild yak population. The English word "yak" derives from the Tibetan (Tibetan: Wylie: g.yag), or gyag – 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.

http://en.wikipedia.org/wiki/Yak