If "cow" is not an acceptable generic singular, is there one? "Cattle" is plural, and it seems awfully pretentious to say things like "A steer is a castrated male Bos taurus". Lack of a generic singular seems like it could be rather awkward. I mean, if there's a bovine of indeterminate sex in the road, I'm not going to try to figure it out!

Ha, Wikipedia has a whole section on "Singular terminology issue"! Apparently there is no answer to this dilemma, but I'm going to keep calling them "cows" in collective, although I kind of like "cattle beast".