Breeding without inbreeding does not require a PhD. Why anyone would assume that they understand something they have zero knowledge on amazes me. I stated that inbreeding was not an issue yet you seemed to have disregarded that statement. I do not get in the habit of repeating myself nor explaining myself. Hybrid breeding or cross breeding often leads to diminished traits from the original breeds. The further you get from F1, the more diminished some traits are likely to get. Hybrid breeding can also be used to enhance traits, but those rarely endure much beyond F1, at least not at the same rate. Simple chicken genetics.so you used different bloodlines @spartacus_63 ? If not, it was definitely from inbreedin, just plain chicken genetics.
I have found that breeding cross bred cocks and hens from the breeds that I originated with resulted in decreased egg production and broodiness over time. I also found that the most broody hens I ever had were F1 hens from the a RIR over an Orpington. On the down side, the hens tended to be smaller than typical Orpingtons.