We raised 3 chickens for our friend, they r bout ready to be returned now at 11-12 weeks old. They are still on their chick starter, our friend is just using whole flock food. Is it safe for the chickens to just eat whole flock food without slowly introducing it?
It can give them diareah for a week if you change from one food to a different one so be prepared for that and don't panic if it happens To avoid you can mix the two feeds 50/50 for a few weeks.
i feed my flock chick starter/grower till they are 16 weeks old, then i switch to layer pellets. i start introducing them to chick grit at about 1 week, and i start giving them cracked corn as a treat/scratch when they start feathering out. im no expert but it works for me.