I can see why shows insist upon it, because of tradition and insurance, but there is no consistent logic to ringing a bull for safety reasons. On the horse side they may insist upon pain inflicting devices such as bits for ridden horses, but the in-hand classes have no such requirement. Horses can be much bigger and certainly more flighty than bulls, and so can some cows. I've seen a few cases of cattle getting away on people at shows, but they have always been cows or youngstock. You could, I suppose, say this is proof that ringing works, and that'd probably be right, but then why not ring all mature show animals?
I hate to see the AI pictures where they are using the ring to lift the bull's head up and then photoshop out either the ring or the rope pulling on the ring. That is both an immediate red flag to me that the photo has been manipulated and also an indication that the bulls temperament may be less than ideal.
Bull nose ring
Re: Bull nose ring
Can't say we have had any trouble having had nose rings put in but we have to be more careful about places that the bull could get it caught up. Vet gives injection in nose (presume it is the same stuff for disbudding?) and uses a bull punch to make the hole.
The Alvecote Herd
http://www.alvecotedexters.net
http://www.alvecotedexters.net