A Dzo is a male hybrid of a yak and a domesticated cow. They are larger and stronger than cattle, and are bred for agricultural work in Nepal. Alternative spelling in English: zho (or zo as per Tormont Webster's Illustrated Encyclopedic Dictionary). A female offspring is known as a zhom.
In Nepal, yak/cow hybrids are bred using yak bulls on domestic cows or, less often, domestic bulls on yak cows. The female hybrids are fertile, the male ones are sterile and the meat is considered superior to beef. In Nepalese, the hybrid is called a Khainag or Dzo (male) / Dzomo (female). A Dzomo crossed with either a domestic bull or yak bull results in an Ortoom (three-quarter-bred) and an Ortoom crossed with a domestic bull or yak bull results in a Usanguzee (one-eighth-bred). As a result, many supposedly pure yak or pure cattle probably carry a dash of each other's genetic material, respectively.
There is as well a more or less English-derived name, Yakow, which is a Portmanteau word, an obvious combination of the two words yak and cow.