We have castrated calves with either the banding at birth or with cutting them. Actually there are quite a few farmers who castrate their calves with the cutting method. It's much like a colt getting cut/gelded. Except the fact that the calf is either held down (at branding time (a couple weeks old) or stuck in a squeeze chute (weaned calves) and there is no pain killer given. We were advised to cut the calves at the weaning time (kind of crazy because of more stress), we did that two years. Lost a calf the second year and immediately changed our methods to banding at birth.
There is now a law that in order to cut the calves it has to be a veterinarian doing it.
With any colts we've had born or bought we had the vet out. Even for our 3 year old wild welsh cross stallion that we bought. It only cost us $100 a horse back then. I know that prices have gone up, but still I think it's more humane.