You may have seen it, but an interesting video about the factory in Hungary.
http://poultry.proultry.com/products/babolna-tetra-kft/tetra-sl
Also, I think Tetra layers are also a 2nd generation as in the beginning of the video the rooster are white and towards the end the hens are pure white, look like some Plymouth Rock but not sure.
http://poultry.proultry.com/products/babolna-tetra-kft/tetra-sl
Also, I think Tetra layers are also a 2nd generation as in the beginning of the video the rooster are white and towards the end the hens are pure white, look like some Plymouth Rock but not sure.