Yes! I have cornish cross mixes in the big brooder now. They doubled the weight of the leghorns in a few days, even though they're half leghorn themselves. The fertility rate seems like it's about the same as the other hens. I'm still waiting to hatch my first turkeys, but they've had 100% fertility so far, minus one that froze. My incubator fried the first batches, but I have several in there now.