My god...Did you permanently bend the trailer? I would think shifting a couple bales toward the rear while loading would've been a good idea.
I was out delivering (when am I not?) and had two newer Dmaxes go by me pulling large trailers loaded with round bales. I could've sworn I counted 18 bales on the one trailer, double row, 5 on bottom, 4 on top. The other was almost as many.