Dzo Dzo A dzo (Tibetan མཛོ་ mdzo) (also spelled zo, zho and dzho) is a hybrid between the yak and domestic cattle. The word dzo technically refers to a male hybrid, while a female is known as a "dzomo" or "zhom". In Mongolian it is called khainag (хайнаг). There is also the English language portmanteau term of yattle, a combination of the words yak and cattle, as well as yakow, a combination of the words yak and cow. Dzomo are fertile (or, fecund) while dzo are sterile. As they are a product of the hybrid genetic phenomenon of heterosis (hybrid vigor),
Wild animal suffering having greater levels of cortisol and elevated stress responses relative to domestic animals. Additionally, unlike domestic animals, animals in the wild do not have some of their needs provided for them by human caretakers. Welfare economist Yew-Kwang Ng has written that evolutionary dynamics can lead to animal welfare which is worse than necessary for a given population equilibrium. In the essay 'On Nature', utilitarian philosopher John Stuart Mill wrote about suffering in nature and the normativity of struggling against it: In sober truth, nearly all the things which men are hanged or imprisoned for doing to one another, are nature's