I have 4 faverolle hens that are 1 1/2 years old and 6 buff orpingtons 16 weeks old this next saturday. I just ran out of feed. Can I go ahead and buy layer crumble when they are 16 weeks? I switched my whole flock to chick crumble and I'm dying to go back to layer crumble. It costs like 20 more dollars to get orangutan chick nonmedicated crumble.