I have a 15.2 hh yearling WB that I want to start trailer training. My problem is that I bought a big 2 horse straight load WB size trailer. He has trailered in it with the partition out, but I want to start teaching him to trailer "like a big boy". He does tie, but the trailer stall is about 10 feet long from chest bar to butt bar. If I tie him and push him up against the chest bar, there's about 5 feet behind him to the butt bar. If I tie him so that he hits the butt bar before hitting the end of his tie rope, he is 5 feet back from the chest bar....
Any advice? Do I just have to wait until he get bigger?
If he's 15.2 as a yearling he'll get there quickly. In the meantime I'd be more concerned with getting him tied safely than with letting his butt hit the butt bar....that'll happen as he gets older/bigger but he needs to know to go to the front of the stall and stand tied there safely. If you give him enough lead to bump his butt against the butt bar he's going to be way too loose in front and could get a leg over the lead and have a major wreck. He'll eventually begin to bump the butt bar gradually as he gets bigger so it won't be like it reached out and bit him.
Based on my own limited experience, here is what worked for me
I use a straight load 2 horse trailer where my filly comes no where near the end/butt bar, walls or ceiling. I think this is great, because she doesn't feel enclosed/trapped like some large horses might.
The first time we loaded I had zero expectations. She walked right on. I led her on and backed her off the trailer 3 x (she had never backed off before--step down). When on, she got grain in the feeder (it has a manger) and then we hung out. She was totally unconcerned, didn't even poop. I think the biggest thing that helped was loading her with a seasoned, good loader that was also a buddy. She took her cues from her friend and never questioned being on there.
The second time we went on a short trip--about 7 miles (friend was also along). We tied her a bit shorter than the trailer tie (I think they are long though). Tieing was after the butt bar was in place and the rear door was shut. "Short" so she couldn't rear up, and also because we wanted to see what happened when she hit the end of the rope and realized she was tied. She hit the end and stepped forward (confirming our tie training in the arena, etc.).
Then her third trailer ride was to a show about 3.5 hours away. This time she was tied short and also had a hay bag. No issues about trailering at all there or on the return trip.
I want to take credit, but I did nothing except make sure she first understood tieing at home (and leading/backing), introduced the trailer with no expectations of going anywhere that day, and had a really good trailering buddy along. I did have a helper so the back door could be closed before I tied her. She had trailered in a stock before, so it wasn't like the idea of moving was completely foreign.
Her mom was a fantastic loader too and they did haul to the vet clinic together several times for breeding. I kind of doubt she remembers that though.
Sorry for the novel!
I would never tie long enough to hit the butt bar with the babies--way too easy to get a leg over the rope!