No knowledge with
cattle I can share. However, as a teen I went to New Zealand for a year as an exchange student. During that year they arranged for the
city kids to get to spend a week in the country (and vice versa). So I spent a week on a sheep farm, during lambing season. Helped the farmer with tailing and castrating. Both were done with bands. I will say it seemed fairly simple. Myself and the other exchange student that stayed on that farm would lift the lambs up holding both front legs, and one hind leg, and put their butt on a
wood plank about hip high. The farmer would then put a band around the base of the tail, and if a ramling around the scrotum. Once released the lambs would kick for about 30-60 seconds until everything went numb and then they'd calm down.
Biggest issue I remember with the castrating was making sure you got both testicles. If one hasn't descended yet the band won't get it, obviously. In that case you'd need to wait until it descends or go the surgical route.