http://www.e621.net/tag_implication?query=bovine is all inconsistent now. Admittedly the current {cow,bull}→bovine is bad too, but antelope→bovine is worse (if tags are about common usage).

Common English meaning of "bovine" pretty much means <i>Bos taurus</i>. Maybe we should be using full-on taxonomic notation, tx:bovinae or tx:vulpini maybe. Or maybe not because they'<del>re completely fucking imaginary</del>d have their own classification, in reality :)