Yak is a cousin of a domestic cow. Probably not a lot difference in flavor
https://www.quora.com/What-do-yaks-and-water-buffaloes-have-in-common
[snip] Anthony Davies
What are alikes between a yak and a water buffalo?
They are both bovids, members of the bovini or cattle family , they are both used as meat animals and as beasts of burden, and for milk , butter and cheese production, but they are very different. Yaks are closer to taurine cattle and bison , American bison specifically, and can interbreed with either producing fertile female progeny. Domestic yaks at least are a relatively small member of the bovini tribe, cold and high altitude adapted with a thick double coat of long hair. They have typical cattle horns with a circular cross section tapering to a sharp point. Water buffalo are one of the largest of the bovini, evolved to suit a tropical, semi aquatic environment. They are almost hairless as adults, Asian swamp buffalo have massive horns that are flattened in cross section. The long domesticated riverine buffalo have smaller curved horns more like those of domestic cattle. [/snip]