I have a flock of mixed ages housed together... 13 of them are laying now, and 8 of them are just 16 weeks old. I feed everyone a grower feed and have oyster shell available. (The new layers are going thru the oyster shell like it's candy! Nice egg size/quality though... just a LOT of oyster shell is being taken in!) I'd like to eventually switch to a layer crumble, but do I absolutely need to wait until the younger ones are laying (or at least very close), or are they approaching close enough/safe enough age to handle the layer crumble without causing health issues? The young ones should be around 20 weeks before I need to buy feed again...but if I'm going to do a switch, I'd like to do a mix for a week or two to ease them into it. (I may also try another brand-- the main reason for doing a mix for so long) On the feed brands- I'm currently feeding ADM grower crumbles and don't have any complaints. I'm a fan of ADM in the horse feed line. I'm considering changing to Nutrena for the chickens... mostly because it's about $6 less a bag and at a closer location. Not exactly a budget buster amount... but, you know... Some of my older pullets have JUST started laying in the last month (or even week!), FINALLY! I don't want to throw them off somehow with a feed change. Any experience/opinions or pros/cons of Nutrena chicken feed? Anyone actually use ADM and Nutrena and have opinions on how their flock did on each one? Thanks!