So today the freedom rangers are 11 weeks old and I weighed the biggest one we have and he came up to 4 lbs 10 oz but felt small still. Would it hurt to hold them til they turn 16 weeks? Would it help if I add the heat lamp back? It's been cold and snowing here in TN which isn't normal for Dec. My CornishX didn't even get as big as they should been. My other FR's are so much smaller than the one I weighed. What'd be the longest you'd hold chickens over that you sell to family??