Beefalo Bull.

Beefalo Bull.
This bull is a Beefalo bull, a cross between Bison bison and Bos taurus. This is not necessarily an F1 cross. Fertility in the F1 generation was generally poor. In crosses between the bison bull and domestic cow, cases of hydrallantois are common, as a result of placental dysfunction.

Drost M (1976)