I found this study online that some of you may have stumbled on by the way of Google as I myself did back a few months ago. The study is titled cross breeding of poultry. It was produced by Kansas state college of ag and applied science in 1942. They have multiple studies available online. I printed every one I could find and have read almost every word of all of them. It's written in the most scientific terms of the times. Since it was conducted and written prior to 1950 it's really plain English now days. Sorry I wrote a book but it would be an absolute sin not to share this info. I'm a total nerd when it comes to agriscience and husbandry. Any ways look it up if ya get a chance and have a couple hrs to burn reading. The study on sexing hatchlings is also great.