I've heard they have a huge problem breeding because of the large breast and weak joints.
I'm not sure what the other cross is. I just know the cornish hen part. Lol
I believe the cornish cross is made by breeding a cornish hen to another breed of bird I cant remember.
I dont think the hatcheries are breeding the cornish cross with each other to get more cornish cross, but instead have a breeding pen with the cornish games heans + whatever rooster you use...