Not really. Different blood lines and blends soemtimes throw a certain type of horn, for example certain blood lines have the twist horn gene and others don't. Both heifers and bulls grow at about the same rate. Of course, some animals will be the exception to this. Normal horn growth is about 2-2 1/2 inches per month for the first few months. It slows down later but continues to grow. I think a bull has peaked at about five years old but will still grow a little. Cows will still grow an inch per year on an average after ten years old.