I got my new birds from Mike Stichler, so I doubt if they have had any recent Barred Rock in their lineage. He selects for larger frames and he was very detailed in his descriptions of his search for "new blood" to provide appropriate genetic variations in his lines over the years. However, I can only assume that when many breeders were trying to revive the breed back in the 70's, they sought out the closest breed to the Doms in an attempt to maintain the look of the breed. I can't wait to compare my hatchery Doms to these new girls side by side (new girls are still in quarantine, so it will have to wait for now). Even apart, several differences aside from size stand out. The coloration on the hatchery birds is closer to barring, while the new Doms have the true cuckoo pattern. The hatchery birds are also black and white while the new ones are the ideal dark gray and off white. I would guess (and truly nothing against hatcheries, as I don't have a word of complaint about our birds from there--but we knew buying them that they would not be close to the SOP) that the hatcheries have used Barred Rock much more recently to round out their genetics. We are very new to this breed and look forward to working with it (and if I made any blatant errors in my descriptions, I welcome corrections--I have struggled a bit trying to learn what exactly to look for!).