Yeah, but the broiler breeders aren't as heavy as the actual broilers they produce, so you can get them to lay for a season pretty well. Whereas the final product, the chicks, are really hard to get and keep laying because they get so large.I know I am late to the discussion, but there's a farm near me that has broiler breeders - thousands of Cornish Crosses, both hens and roosters (one of the industrial strains, not sure which), and they have no trouble getting these birds to reproduce. They lay very large off white to cream colored eggs. They keep them for a year, then "recycle" them. So, it can be done. These birds have their feed tightly regulated, which as I understand it, is required to get them to adulthood. From my research, they are free fed for the first 5 days, then get food with held for 12 hours a day, to slow growth.
Not sure what mortality is after a year though. They all become soup meat. But they are early and fairly prolific layers, laying from 20-26 weeks, and each house of 10,000 chickens (no idea hen/rooster ratio) produces 6-8,000 eggs a day, which is a daily or every other day layer. This farm is specifically a farm for hatching eggs to make little broiler babies.