Well I'm thinking the balance in nutrition is lacking and I'd only free range a couple hours a day. I feed my birds a Grower finisher feed and supply Oyster shell once a week. Mine get a small treat twice a week and free range about 2 hours a day.They get a layer feed from the mill, I don’t give them oyster shell. Do they need that too? The mash I get from the mill was supposed to have everything they need, or at least that’s the impression I got when I was switching them from the Purina feed I used to get from tractor supply. They free range from 630 am until they go in on their own at night.