" Never been able to figure out why so many young healthy guys PAY to lift weights at the gym, but are scarcer than hen's teeth when I'd be glad to pay them to lift and stack hay."
That right there is the reason the big round baler was invented.
Read up on Vermeer balers. A couple of neighboring farmers had a conversation where one of them was selling his cattle because he couldn't get any help with the hay. His buddy didn't want him to quit. He started out with an idea, made a cardboard model and then started fabricating.
When the first round baler was made, by Vermeer, it required a fence post to be put in the throat of the baler to get the hay to start to wrap. Well, the post became a part of the bale because it was wrapped in there tight.
When the bale was fed the post showed up again and was set aside to reuse for the next hay crop. The first 6' round bales were made by a 600 series baler. I've got a 605C that has to be an antique. It takes a special amount of patience to get the hay to start wrapping and to know when to quit and clean out what isn't going to wrap!
The first round baler was made by Allis Chalmers, back in the 40's, came from a farmer who invented it back in 1910. It was the basis for all those that followed. Although the bale was small, about 100 lbs, 36" by up to 25" in diameter, it could be left out in the field, for later removal, or just let the cows eat at will, in the winter. I used to take my 4 wheeler, and home-made snow plow, and push a pile of about 10, toward the center of the field. Then 10 from the other direction for a pile of about 20. Pull up between 2 piles, with a F-350 dump truck, and load 2 piles, pull forward, and get most of 1 more pile. Up to the barn, and dump. Pretty efficient for a 1 man show. You had to use 2 hay hooks, to handle them mothers.
Had a lot of fun, with my piece of history (hey, it was orange!) If my back was in better shape, I might still have it. Here is a little article, on the AC baler...
http://www.farmcollector.com/implements/spin-on-roto-baler-round-bales.aspx