I thought I'd come read up on Cream Legbars as I adopted four this past spring. I ordered all pullets and got two boys; so much for auto sexing! But I looked at the photos of Blackbirds13--beauties!-- and my roo (the other died at four days old) looks nothing like them and I'm wondering just what I have on my hands! Are there different breeds within the breed? Did I get super duped? Please advise! AND I'm off to read more.
Last year or two there were bad rumors circling that you had to cross your Legbar to a Leghorn or a PBR to produce viable offspring. While crossing to a Brown Leghorn is possible for new blood it takes culling all male offspring and a couple of generations to ensure the gentetics of the cresting, cream color, and Autosexing again (although the blue eggs usually stay blue). A cross not monitored can steer birds off course very quickly, and that may be what happened in your offspring. I doubt most breeders would intend to dupe people.
Best wishes with your birds, and you may find more help if you post in the cream legbar or alternative Legbar threads.