One is his hatch mate and the other is a little older but same linesSo you say the hens are better to use then the cockerel? What about the white feathers on the one hen, will that cause more problems then it’s worth?
You can test mate the hen with the white feather by breeding her to a Cock that is free of parasitic white (no white feathers or under fluff/down). Hatch 10 chicks then grow them out to maturity. If the hen has parasitic white then in theory half of these chicks will express parasitic white.