Like horses, I think you are supposed to teach them when they are only 80 pounds ;~D
My son went with his Ag teacher to pick up his cute little under 80 lb little calf. AWWW how cute it was going to be. He come back with a baby cow from hell that got bigger every day. a real head butter. She went nuts during the practice show and there was talk from grown ranchers about shooting her. Our mild mannered vet were using words I had never heard before. My son just kept working with her though. He really did use his dads old truck and taught her to lead. It didn't hurt her. Just made her mad. Not something for a sweet little pony though.
We took the truck away from him when the ran it into the side of the house though(he wasn't pulling the cow at the time) :')