What kind of feed are they on? Just corn and bugs or do they have another kind? If it's just free range and corn and stuff I'd recommend finding euther a layer feed or all flock feed. Probably an all flock since you also have roosters and ducks and then just give calcium via free choice oyster shell or similar for the layers. Free range can work but sometimes it doesn't and in your case it may not be. Plus it's nice knowing its a complete feed and all the nutrients are in there. Nutrena makes an All Flock as well as another similar kind i cant remember the name of atm but ones nature wise or nature smart and ones country feed lines, and purina makes one called flock raiser. Both are good but I'm going to be buying nutrena. I'd highly recommend buying feed, it's not too too much either especially compared to all the organic stuff out there.
If you already have them on a feed then feel free to ignore this and sorry
If you already have them on a feed then feel free to ignore this and sorry