I've had them for 1-7 years. A few are good weight, but I"m always thinking they are thin. They have free choice feed, treats, they are wormed and dusted. By thin I mean I can feel the breast bone more than I like but can't pinch it. Maybe I'm worrying about nothing. Maybe chickens don't all look like oven stuffer roasters. I'd still like more heft to them. What can I do?