I don't know anything about nose rings, but will he walk on halter without a nose ring? We can get anything in from little ones on bottle or momma to ones just halter broken on the trailer. What we do is get in the trailer and pull the lead and keep the pressure on the rope and have someone wack their rear if they aren't moving. With some of them than seem to be a little less smart or can't get their feet up, we lift one front leg up on there and keep pulling. If they still don't go, keep the lead tight and move to another side inside the trailer so his head turns. I don't think you would have to resort to a prod, but if you need to use more force some way do it. If you aren't strong enough to keep the rope tight you can slide it past one of the bars and have someone pull it against the bar on the outside of the trailer. He needs to learn to go when you tell him to. I would throw feed in after he's gotten in, not before. He's going to see that as his way of training you, if there's feed, he decides he wants to go in. In own experience and training people, I've seen animals messed up and gone unruly with feed being used.