Here in North America, most bulls have their heads shaved before going to a show or sale.. regardless of age. In Britain, they don't want the bulls head shaved as they feel that a good bull has to have curly hair on his head as that is a sign of masculinity. When I was young, my dad would never consider buying a herd bull if he did not have adequate curl to the hair on his head. He still believes this, and oftentime says that some of the herd bulls I have don't have enough curl to the hair on their foreheads. I really think I would have to look for awhile to find a bull with enough curl to suite him today. Maybe it is an old wive's tale, I am not sure but there are many things that have been completely forgotten about today, that were extremely important to cattle breeders in the past. My grandfather would never buy a herd bull if he could not put his hand around his tail at the twist of the animal. He said you should just be able to get your fingers to touch around the tail of a 2 year old bull in order for him to be a good breeding bull. If he could easily touch his fingers, he would not buy him no matter how good he looked. Today there are not many bulls sold as 2 year olds but I often wonder if there was any merit to this or just more folklure from the past.
I do believe we have to understand what masculinity looks like. For example, when you breed animals to improve muscling, you add muscle over the entire body not just in any one location. This means there is going to be more shoulder on an animal with more muscling. The shoulder is held in position by two large muscles .. one on each side. There is no shoulder joint. What is the most important factor in determining calving ease in a masculine bull is the angle of the shoulder. By this, it means that there has to be adequate slope from the elbow to the top of the shoulder blade. If this is too straight, there will be more calving problems. Animals with posty hind legs will also be too straight in their shoulder. Is it any wonder why many clubby bulls are harder calving? Mother Nature has been pretty good in designing these critters to function properly, but humans have screwed around trying to make these animals more pleasant to the eye. I would far rather have an animal with too much set to his hind legs than one with straight legs. I have never seen a bull with too much set in his wheels have to be shipped to market because he could not get around to breed the cows. I have seen countless numbers of posty legged bulls have their lives ended at young ages.
If you want to get some good lessons in structure and function, you only have to look at animals in nature. There are plenty of good lessons to be learned.