I discipline my young ones. I use chained lead ropes, and whenever they, lets say bite me, I will pull the chain. I kick my horse in the gut as well, but I do it with my toe, and my horse loves me to death. I'll use the bite example again, say Hoopie, 2 year-old mare, bites me, I'm going to either pull down the chain, or hit her in the face, as mean as that may sound, she has discipline and now knows what is acceptable and not.
"Doing what you like is freedom, liking what you do is happiness."