I love it when people start adding rules to nature. LOL!
I'm a newbie you might say only having chickens for the first time in my life and they are 7+ months old.
Sure, we fed medicated chick feed to our birds … because we wanted to be successful our first go around. However, I have no doubt mama hen knows more about raising her babies than any one person or any group of people … that is if they're a broody bird to begin with. I have no doubt mama hen would have any difficulty raising her chicks in a free range environment, especially during spring and summer time, all on a natural diet where no feed is supplemented. I don't do this, but I'm sure there are plenty of people that rarely give their birds anything except for in the winter time, and I wouldn't be afraid to try it once I gain more chicken raising experience. If I thought I could raise them on zero feed dollars I'd be all over it. We currently feed Purina feed to our birds. Come spring time I plan on letting them gather their own food free ranging while I'm also growing plenty for them in our garden.