The two are part of my regular laying flock. And I of course verified they were in lay when I separated them into the tractor for breeding.
All I can say is they certainly lay eggs, they are several pounds heavier than any of my other hens and they surely eat more food. As far as layers go, they wouldn't be considered efficient... but that's not why I kept them.
digitS' :
Since the sire is 1/2 the breeder flock and is primarily there to contribute meat-building genes to the chicks, doesn't that mean that the dams are there primarily to produce lots of eggs (hence, chicks) and so, perhaps, you should stay solely with the Black Sex-links? Or, you may wish to explore using some of those other highly productive laying breeds.
Yes and no. I don't need the offspring to ever produce, so it's only the parent strains I care about the egg laying ability in. And even then, they only need to lay enough for me to hatch a clutch of maybe 25 birds at a time.
Commercially raised Cornish Crosses are actually double crosses from separate Cornish and Rock strains (1 for meat, 1 for laying). So they get heterosis twice between the two matings.
I also think that since my Dark Cornish is so unrelated to any 'Cornish' being used in the broiler industry that I get a fair amount of heterosis in these matings as well. So, why did I choose black sex links? Because among all my hens, they are certainly the largest (due to their crossbreeding). The Cornish Sire himself is nothing special as far as meat goes, he is simply providing the lenght/width to the breast and the dame providing the thickness (hopefully).
digitS' :
I'm just wondering if the FR breeder hens are worth their feed since maintenance could far exceed production. And, keep in mind that I know nothing about this hybrid outside of the fine looking pictures I've seen of 'em.
For me, they are woth it. They contain genes in them that I could never obtain within my lifetime. So I think rebreeding them, even though they don't "breed true", is giving me access to growth rates and genes I could never obtain myself starting entirely with a flock selected for laying ability.
Awesome questions. I wish I could answer them better. But at this point in time, it's all just a science experiment which ends in good quality chicken to eat. It's second only to my cider making, which is a grand science experiment ending in alcohol.