Pinched tails arent a breed-specific trait, it's a physiological defect that works against laying hens. Hobby or registered breeders who conform to a breed's SOP will select against any negative traits that pop up in their flock, so they wouldn't hatch out eggs from hens who displayed those negative traits, but hatcheries have hundreds if not thousands of animals and tend to select for form over function -- animals that look cool but don't necessarily meet the Standard. You can compare a hatchery Rhode Island Red with an RIR that meets the SOP and see quite a difference.I didn't know about the tail aspect. What breeds have the pinched tails and what does one look like?