We have 12 pullets, 1 roo all bought together,about4&1/2 wks. ago, all red comets about 5 weeks old. They're very healthy and happy outside (NE Florida, 68°at night)in a nice covered pen with a roost and plenty of room to wander. Later we also bought 2 Dominickers, 2 black Americaunas and 2 lavender Australorps. The newer babies seem much more delicate. They're about 2 weeks old now. Both of the black Australorps died :'( The others just seem more fragile, just not as overall healthy. (Bought from same hatchery, very reputable) We switched from all corn start and grow to the darker, medicated start and grow, thinking it would be better. Now I'm not so sure. Have had one with pasty butt, idk... Any ideas, advice, please.