Heritage chicken breeds maintained by small-scale keepers and conservation programmes have dramatically better welfare profiles than commercial lines but face economic pressure.
Heritage breed welfare is inherently superior to commercial selection: breeds developed over centuries for foraging, environmental adaptability, and natural reproduction have health profiles that intensive selection has systematically degraded in commercial lines. A Dorking chicken can run, flap, mate naturally, and maintain body weight to old age; a commercial broiler cannot do any of these things effectively. The welfare case for heritage breed preservation is simultaneously a welfare argument, a genetic diversity argument, and a cultural heritage argument.