Dzo
In its own language: མཛོ་
A yak-cow hybrid from Tibet and Mongolia, bigger than either parent
The dzo is the hybrid of a yak and a domestic cow, bred in Tibet and Mongolia. Males are sterile, females called dzomo can breed, and the cross grows larger and stronger than either parent, giving more milk and meat and coping better with high altitude.
- A dzo is the hybrid offspring of a yak and a domestic cow
- Males are sterile; females, called dzomo or zhom, can breed
- Mongolian speakers call the animal khainag (хайнаг)
- A khainag crossed back to yak or cattle gives an ortoom, three-quarter bred
- English also has the blend words yattle and yakow
What do Dzo cattle look like?
A dzo is not a breed but a cross: the young of a yak and a domestic cow. English speakers sometimes call it a yattle, a blend of yak and cattle, or a yakow. The Tibetan word dzo properly means the male hybrid, which is sterile, while the female, a dzomo or zhom, can breed. Mongolian speakers say khainag. Because two different parental lines are brought together, the offspring show hybrid vigour, or heterosis, and grow larger and stronger than the yaks or cattle of the same district. They take one kind of protein from each parent, which alters their mitochondria, the energy centres of the cell, and helps them live higher up than either parent manages.
Where does the Dzo come from?
Dzo are found wherever yaks and cattle are herded together, above all in Tibet and Mongolia. The Tibetan name མཛོ་ is written mdzo in Roman letters and names the male animal; Mongolian herders call it khainag (хайнаг). Since the fertile females can be bred back, the two parent species have been mixing for a long time, and many animals taken for pure yak or pure cattle probably carry some of the other's genes. Mongolian practice names each stage: a khainag crossed with a yak bull or a domestic bull gives an ortoom (ортоом), or three-quarter bred, and an ortoom crossed again gives a usan güzee (усан гүзээ), or one-eighth bred.
What the Dzo is known for
The hybrid's chief merit is vigour. Dzo are larger and stronger than the yaks or cattle around them, and in Tibet and Mongolia they are held to give more milk and more meat than either parent. Their mixed inheritance also seems to suit thin air: they carry proteins from both sides, their mitochondria differ as a result, and this is thought to strengthen their ability to live at great height. Males cannot reproduce, so the line is continued through the fertile females and their back-crosses rather than from dzo parents.
How the Dzo is bred and kept
Breeding works by crossing and back-crossing. A dzomo, the fertile female hybrid, can be put back to a yak or to a domestic bull. In Mongolia the result is an ortoom, a three-quarter-bred animal, and a further cross produces a usan güzee, one-eighth bred. Because the males are sterile, a dzo cannot serve as a breeding bull, so first-cross hybrids must be produced again from yak and cattle parents in every generation. This steady traffic of genes in both directions means that herds described as pure yak or pure cattle may in fact carry genetic material from the other species.
Dzo, drawn
What the Dzo is kept for
Dzo are kept for milk and for meat. In both Tibet and Mongolia they are thought to outdo the local cattle and the local yaks on both counts, which is the practical reason for breeding them at all. The females, the dzomo, are the ones that give milk, and they have the further advantage of being fertile, so they can be mated on to produce the next generation of back-crosses. Size and strength, the fruit of hybrid vigour, make for a heavier animal than either parent, which suits a household that wants meat as well as milk.
The land and climate of the Dzo
Dzo belong to the high country of Tibet and Mongolia, where yak herds and cattle herds use the same grazing. Their double inheritance shows in their cells: they carry two kinds of protein, one from each parent, and their mitochondria work differently as a result. This is what is thought to let them thrive at greater heights than either the yak or the domestic cow. Thin air, cold nights and open pasture suit them, and the value of the cross rises with the altitude of the farm.
Who keeps the Dzo
No single community is named as the keeper of dzo. They appear wherever yak and cattle herds are run together, which in practice means the herding lands of Tibet and Mongolia. Mongolian speakers have their own word, khainag, and a graded set of terms for each stage of back-crossing, which points to long familiarity among the herders of the Mongolian grasslands. Tibetan speakers, who call the animal མཛོ་, likewise keep both parent species in the same high country. The hybrid belongs to ordinary mixed herding rather than to one people or caste.
At a glance: where it belongs
Land and climate
Custom and folk tradition
Mixed herding has given the dzo a settled place in the working vocabulary of the region. Mongolian herders grade each stage of the back-cross with its own name, from khainag through ortoom to usan güzee, a sign of how long the cross has been part of ordinary practice. In Tibet the animal has one word, མཛོ་, and the female another, dzomo. The short English word has a small life of its own as well: spelt zho or zo, it is a handy Scrabble tile, and it sits in dictionaries beside its longer cousins, yattle and yakow.
Numbers, conservation and the herd book
Being a first-cross hybrid rather than a breed, the dzo has no herd book or breed society of its own. Fresh animals are produced by mating yaks with domestic cattle, generation after generation, since the males are sterile and cannot pass the cross on. Numbers therefore follow the number of places where the two parent species graze the same ground, above all in Tibet and Mongolia. Back-crossing has gone on so long that many animals thought to be pure yak or pure cattle probably carry the other species' genetic material.
From the Dzo
Questions people ask about Dzo
What is a dzo?
It is the hybrid between a yak and a domestic cow. The word properly means the male hybrid; a female is a dzomo or zhom. In Mongolian the animal is a khainag, and English speakers sometimes say yattle or yakow.
Where do dzo come from?
They are bred in Tibet and Mongolia, wherever yak and cattle herds share the same grazing. The English word comes from the Tibetan མཛོ་, while Mongolian herders have their own term, khainag, and names for each stage of back-crossing.
Can dzo breed?
The males cannot, as they are sterile. Females are fertile, though, and can be back-crossed to a yak or a domestic bull. In Mongolia that cross gives an ortoom, or three-quarter bred, and a further cross gives a usan güzee.
What are dzo kept for?
Milk and meat. In Mongolia and Tibet they are thought to give more of both than the local cattle or yaks, and they grow larger and stronger than either parent, a result of hybrid vigour, or heterosis.
Why do dzo do well at high altitude?
They inherit a different protein from each parent, which changes their mitochondria, the energy centres of the cell. This is thought to help them live at greater heights than either the yak or the domestic cow.
Good reading and sources
- Dzo on WikipediaEncyclopedia
- More photos on Wikimedia CommonsPhotos and video
- Wikidata recordOpen data
The facts on this page come from the Wikipedia article "Dzo", written by its contributors and used under the CC BY-SA 4.0 licence, and from its Wikidata record (CC0). EveryCow rewrote the text in its own words, with AI assistance, and compares every page with the article to make sure no passage is copied. It may be reused under the same CC BY-SA 4.0 licence with a link back.
It may contain mistakes. Sizes, colours and customs differ from one herd, valley or breeder to the next. Folk beliefs are described as tradition, never as advice. If something is wrong, tell us. Last refreshed 2026-10-16.
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