: Does the male or female genes determines the sex of an animal? How much does a bull contributes to the calf? I mean a black bull with a white cow could produce a white cow. How is that? Thanks<p>Jason;<br>I appreciate your response. I have an eight year old cow that has had 6 bull calves and I have wondered how that could happen. Apparently her PH is rejecting the y chromosome. Her dam was 75% brangus and her sire, (AI) was Exacto, one of the best bulls in the breed. I say that only to say, she also has stubby little horns. With all that polled background, I've wondered where the horns came from. Her calves look good and sell well so she will be around for awhile. Thanks for your response and Thanks to you Billy for your time. <br>Mack<p>