Just to expand a tiny bit on what Fred said...
They're mutts. Their offspring will be mutts, and will not be identifiable at birth. That does not mean they won't be good producers, nor does it mean they will be good producers.
If you're looking to produce chicks for sale where you can guarantee your customers are buying pullets, you will need two purebred lines. As Ridgerunner pointed out to me a few days ago, for those sex-linked chicks to be reliable producers, both parent lines should show good production.
If you just turn them all loose and let them have at it for a couple generations you'll get a jumbled mess of chicks, none of which can be reliably sexed at birth.
They're mutts. Their offspring will be mutts, and will not be identifiable at birth. That does not mean they won't be good producers, nor does it mean they will be good producers.
If you're looking to produce chicks for sale where you can guarantee your customers are buying pullets, you will need two purebred lines. As Ridgerunner pointed out to me a few days ago, for those sex-linked chicks to be reliable producers, both parent lines should show good production.
If you just turn them all loose and let them have at it for a couple generations you'll get a jumbled mess of chicks, none of which can be reliably sexed at birth.