I'm having the same problem with 1 year old ladies that we moved out of the barn coop into the tractor. We butchered 3 roosters that were pestering them and my children. 2 New Hampshire Reds and 1 Dominique. We were hoping that after we killed the extra roosters, and put them in the cozy tractor they would go broody. They hated not having their nest boxes, since that's where the new chicks are, there's no access. We found a couple hidden eggs, and some with no shells, but now there's none! We're adding oyster shells to their feed. Is it the stress of being kicked out, or is our rooster of choice not up to snuff? We feed organic grains and leftover buggy food from my natural food place of employment. They free range all day. I may try and easter egg hunt, then I may put a nest box in the tractor and lock'em up!