The word 'cow' specifically refers to one sex-FEMALE. But we often mistakenly use the word cow no matter what the sex, age or breed they are. There's a whole world of 'bovines' I knew nothing about until now!!!
So my next question is; Can female cows have horns? Answers.com states that almost all breeds are born with buds, the ability to grow horns that are almost always removed at a young age. Sometimes farmers allow them to grow horns, depending on what breed they're raising.
To make this long story short, I believe I have painted a female cow with horns and named her MR. BIG but I'm sticking with it because I like the name! ~ Sharka