There are two kinds of domestic cattle. cattle without shoulder humps like European cattle and humped cattle like the Zebu and other Indian and eastern breeds. both varieties are inter-fertile. Zebus and zebu crossbreeds relatively resistant to heat and so are more commonly raised in the southern U.S. and South America. Humped cattle are shown in Egyptian friezes and were undoubtedly known in ancient Israel and Bavel. When Abaye and Rava had a barbecue, the steaks came from a Zebu or related variety..
Bison, on the other hand, were never farmed until recently and while kosher, may very well be chayos. Other kosher wild animals that are currently farmed are deer, American Elk and Eland (a kind of big antelope) in South Africa.
Interestingly, besides the American bison that we all know, there is a European variety, called Wissent, that is found in eastern Poland and Belarus. The RAMAH must have been familiar with it.