It depends on the confinement, the overcrowding of industrial production may be unadaptable. There are still enough instincts programmed that unfamiliar males

It depends on the confinement, the overcrowding of industrial production may be unadaptable. There are still enough instincts programmed that unfamiliar males would rather avoid each other. I do not beleive that industrial breeding is selecting for anything that makes such prison life tolerable. Birds in production generally aren't reproducing, so nothing in the henhouse is affecting evolution.