I am currently raising 14 pullets ages 8, 5, and 4 weeks. I have never added new hens to my flock before and have read just about every article I could find. My only remaining question is the feed. My older girls are on layer pellet and the young are on starter, soon to be on grower. What do I feed them once they're all together? Should I switch to an all purpose feed till they are old enough to all be eating layer?