I am a chicken farmer just starting out. I raise and sell red and white Cornish chickens. I put them in a brooder house until they are three weeks old then I put them in another pen until they are 8 weeks old then a guy comes out and gets them. my question is this after there 3 weeks old i put them in a pen where my other birds were at is that bad? I don't want any of my birds to get disease and die any ideas on what to do to stop them from getting sick?