As I se it Zed is not a cow (female). If we look at his physiology he must be a hybrid / mix between a bull and a K9, maybe a wolf or a husky, and a body like humans.
Zed has horn like a bull, ears like a dog with pointed ears. He have a broad snout / mussle that may be a mix between bull and K9.
He also have a knot that will grow, just as it does with K9's. The only difference is it only grow if he gets imprinted.
Maybe you will like him better if you think of him this way? Like he does have genes from K9 and therfore might be a wolf hybrid.
I might be wrong of course, but it is my analysis of Zed's psychology. If we compare to known species on earth.
No disrespect, but a cow is female and a bull is male. Both of them is cattle.
Zed is my favourite. I do like the others quite a lot too.