There are heavy oppositions to every side. Natural as possible is best. There are ones that think man can formulate a petri dish concoction that will make everything Super healthy and strong. There have been plenty of cases that have linked manufactured feed to sicknesses and cause of deaths in...
I think chickens are very close to humans. The more natural you can have it the better. With a little added care and love to make it better. If you pay attention they will let you know what is best.