Have been told White Rock & Cornish X. They are substantially bigger than the rest of our flock and are the same age. They are content to eat constantly while our flock finds places to roost which leads me to think Cornish X. But, they have no legs problems and are extremely active. We have fed them the same starter chick food as the others and only have it available in the coop at night, during the day they are free range 6-8hrs and have to find their own meals. The got too hot under the heat lamps at three weeks and had to be moved to a different brooder than the rest of the chicks. I called TSC to see what they ordered 5 weeks ago when we purchased them but are still waiting for the information. At this point we are confused!