It's going to depend on the breeder. Good breeders will be keeping an eye towards production as well as keeping them physically to the type they should have. Some won't. Just like anything else, it will vary. Like, I could sell you a box of chicks from my first mating of these birds in the fall/winter, and those chicks might lay gangbuster, or quite poorly, because I don't know yet myself what I have in the pens.