I purchased 7 Jumbo Cornish x Rocks from Mcmurray hatchery, they were hatched Nov 7 2012, they are now 11 weeks old and doing well for the most part. I have been giving them the Broiler supplement that McMurray suggest with these birds and have not had any leg issues. THEY ARE HUGE. I am thinking of letting them get to breeding age and try to cross them with the other breeds I got in order to increase bird/egg size. Hopefully leading to some really big Brown eggers/Olive Eggers/Easter Eggers. Has anyone tried this?