My Cornish X hens have 1 Roo with them. They are laying eggs every day,and ALL of them so far have been fertile. They started laying at 16 weeks. Most of them are double yokers. I have 2 that are wanting to sit on their eggs,but I won't let them. It's just getting to cold for me to have to worry about lil babes running around. Come spring,if they are all still doing good,I'm planning on letting the raise some babies. I have been reading on here about them not breeding true,and it has made me very Curious as to what the babies would be like. If it wasn't getting so cold,I'd go ahead and let them sit,just to see what they would look like. I have thought about getting some RIR hens. I think some white and red chickens would be pretty.