Halter breaking calves is what started my donkey enterprise. 8) We started with a jack, and he worked very well. Problem was it didn't happen until the boys were in their last year of 4H, so afterwards I had an unemployed hormonally challenged bored donkey on my hands. Then came the jennies, and so it began.
We made a harness out of old round baler belt, and attached a saddle D ring to the side. To keep it from pulling off, we made a breast strap for it as well. It worked just fine, but boy, old Buster didn't like it much. He did, however keep the calves in line, and they learned real quick that following was the easiest way to go. Those donkeys lock their knees, and you ain't movin' em. :wink: :wink: :wink:
Before we got the donkey, we used to do it much like a lot of people here have said. One thing I would add is that, especially if you're working with smaller kids, you must NEVER LET THE CALF GET AWAY! Once they learn that little trick, it's really hard to stop. When it was time for the boys to lead them alone, we'd put an extra halter with a longer rope on the calf, and just tag along as the safety net. Then if the calf bolted, they didn't get away with it. You get a lot of leverage with a fifteen foot rope, so they got a big surprise when they hit the end of Dad's line.
And I agree, if you're going to get a really unruly one, it'll be a heifer every time.