I ran 150 free range layers for a couple of years. Had a couple of old camper trailers, we gutted, and put linoleum down on the entire floor, and build some roosts and hung a couple of sets of metal nest boxes for laying, feeders and water inside. Could move them around "behind the cows". They did a good job of breaking up the cow patties. I'd let them out about 10 in the morning, 2/3 would have laid by then usually, and they got locked up at night. But then the "friendly neighborhood eagle" decided that chicken was a gourmet food on his list. Tried everything to discourage him, but he was something several of those transplanted A$$ holes watched daily; so permanent removal was not an option. Neighbor would watch him (it) carry off a hen everyday. Dropped several in their yard over the year it took it to get 122 hens. I tried keeping them in til late afternoons, and sitting out there and babysitting them for several afternoons.... One time the eagle had one on the ground eating it and acted like it was going to attack me when I tried to scare it off. Should've shot it then...... so that fall I gave them up. Food co-op that I was selling eggs to had decided that they didn't need so many eggs when all the backyard people had eggs to sell in the spring and summer, and I got stuck with about 50 dozen a few times that I donated to the Salvation army shelter.... so when the eagle did that, I just didn't bother to replace them. Co-op got all upset and I told them that you can't put a cork in it to stop the eggs in the spring, after they had begged me to provide more during the fall and winter.....
Now I just raise some purebreds for show, and my own eggs, and get cornish rock x from a poultry house that are too small when they ship birds.....I can feed them for very little for 4-8 weeks, no initial investment in the chicks, all the hard work is done (heat, brooders etc.) and they do a pretty good job of running around eating grass and bugs etc., and then just sell them or put them in the freezer. Works good for the farmer so he doesn't have to kill them and I get free "half grown" birds. Once they get out of the confinement houses, and the crowding, most go on and put weight on pretty fast. They are much sought after at the poultry "flea markets" that we have a few times a year here. Don't make much on them, but I have all the chicken I want to eat, give some to friends, and they taste better because they have been out on the grass etc, doing what chickens do. Don't run them behind the cows now, but hope to be able to move them to another place where they will be able to go out some. Even though they are thought to be stupid, they do seem to adapt to being out pretty well.