Location: Southeast Texas, we have had some great weather lately. In January I bought a dozen chicks - 6 leghorns, 3 delawares and 3 silver laced wyandottes. The flock is around 20 chickens of various ages and breeds + the dozen chicks. The house is 16 x 16 feet, the chicken yard is 1/2 acre, and the chickens free range outside the yard. Chicks were given chick starter for the first 6 weeks, then given laying crumbles. I bought chick grower today and put the whole flock on it. My white leghorns are 2 months old. A week after going to the big house, one of the leghorns has fallen sick and probably will not make it. The leghorns look like they are not doing well, while the silver laced wyandottes look fine. I do this same thing every year. Buy chicks, keep them in a 6 foot X 8 foot enclosed house until they are around 6 weeks old and then move them to the main flock. Rarely, if ever, do I lose a chick that is 2 months old. The main flock is barred rocks, buff orpingtons, rhode island reds, autralorp, dominique.. just your typical dual purpose heritage breeds. None of them have ever had a problem like what the leghorns are having. Compared to the older heritage breeds, how well do leghorns compare?