My 26 CX flock is now down to 8. I lost two during the first two days and everything was going well for the first three weeks. Then I started losing 1 or 2 every few days. Today I lost 8. Tomorrow the remaining birds will be five weeks old. I'm trying to figure out what is going wrong and I think I've figured it out but wanted to see what others think. I have 7 other chickens (layers) that I've been raising with the cx. They are all just fine. They've been raised in the same coop/yard on the same food. They have plenty of water and food is available all the time. Yesterday my son sprayed for bugs in and around the coop at my wife's request. Originally I thought that the pesticide had killed them but the layers are all fine. It seems that if the pesticide would kill the cx that it would also kill the layers. So, I've ruled out the pesticide. And, the pesticide is some organic thing that is supposed to be safe for all animals. I've been feeding all of the birds a 24% game bird protein for the last 3.5 weeks. I live in the Las Vegas valley and its been getting hot - up to 103 today. I have shade for the birds, plenty of water which is kept cool and fans going but its still hot. My thinking is that the cx's just can't handle the heat with their bodies growing so very fast. They are up to about 4 pounds after 5 weeks. The coop is quite clean - hasn't had diseased birds in it before - and is next to the garden so it gets a fair amount of bugs that migrate over which the chickens readily eat. I think I've been feeding them too much protein and that I should have been on an 18% mix so their internal organs had time to keep up with their muscle growth. What do you think? Am I missing something? Thanks in advance!