I've had a couple of my McMurray hatchery chicks die at almost 4 weeks old. They feel and look incredibly thin. I'm worried about the rest of them! My Ideal Hatchery RIRs are just as healthy as they can be and are in the same area. They have all the chicken food they could want (20% protein, baby chick crumble), and water. I can feel the bone in their chest rather clearly, and though they are fat around the rump.. I really have no idea what a healthy chick should feel like. Help?