Hi, I have 2-3 different age groups of chickens and ducks that are all together. My oldest 2 chickens that are 19 weeks old (almost 5 months) I just got my first egg from them last night. I also have a couple birds that are between 12-19 weeks old. I know I need to start feeding layer pellets for the oldest two...should the rest of them just be on grower (what they have been eating)? Should I still put out starter feed or do they no longer need that?