If all you are hauling is hay, im sure it would be no big deal. I used to work around some live floor trailers, but they just didnt hold up to our demo environment. We ended up skinning the bottom of those trailers and using them as drag outs. They really only hauled scrap so there was a mag or orange peel machine at either end.
Something to consider would be a push out trailer. These have a smooth floor bottom. You would have to keep the side walls, but this would allow you to have another trailer to use. Im assuming you are loading the bails with a telehandler, or loader. All you would have to do is load them from the back is stack them up, and push them forward. Once you get to the other end, you just use the ram/pushblock to shove them out the back. Maybe you could rent one to see how it would work for you?