My friend and I got our chickens from the same hatch. We got them when they were around 9 weeks old and her chickens are now so much bigger than mine. Clearly I feed them every day and I have been watching their poo for worms... everything seems healthy but I keep wondering if there is something wrong that I am doing because hers are so much bigger than my girls. She feeds them more "scraps" than I do my girls, like bread and stuff, do you think that could make THAT much of a difference? My girls free range more than hers do too, hers are in a coop and run area most of the time where mine have about 1/8th of an acre to play on.