First how long have you been working him and is out with the other bulls when you're not working him? Not sure how you manage your show calves down there or how old they are when you start, we tend to start our show calves earlier. Along with the nose ring I would pull him in and pen him up away from the other bulls, try and put an animal who is used to being handled with him and feed and water him in the pen. After a few days of getting used to the pen tie him with his head up for a few hours each day. If he continues to act up turn him out and pick another project, getting hurt or even worse is not worth a ribbon.