Mixed age flock/layers bs chcick started

[littlestars17]

My oldest girls(18 weeks began layig today and Im not sure what to feed, I know I need Layer crumbles for the layers, but I also have a rooster and 2 15 week old girls who arent laying yet..Can they all eat the layer crumbles?? Should I mix it?? Advice please?

 

[pkforever]

I feed my mixed aged flock, Flock Raiser, with oyster shell on the side... I read it on here some where...