The giant pink elephant in the room called reality.
First I would like to apologise to
@Aunt Angus for my part in the thread drift. There is no satisfactory answer to your question. I would always choose ranging with commercial feed as backup for any chickens I cared for provided I had chosen the breed of chicken suitable for the circumstances in which they would live.
I’ve read with incredulity on this thread and others extreme views on what should and shouldn’t be fed to what is an omnivorous creature. I’ve read about how much healthier modern chickens are compared to those kept by our grandparents. I’ve read how the science applied to chicken feeding has increased the productivity of the hen and improved the hens health. I’ve read that by ranging chickens where they may eat less than optimal foodstuffs that this may harm there overall health. Then there is the debate based on the safety of the chicken when ranging. For some it is irresponsible to range chickens because of the risk of predation and it is recommended to keep the chickens confined in a secure coop and run.
In the picture below are two hens on their first day out that are the product of these wonderful advances in chicken keeping and chicken health. They’ve eaten nothing but commercial feed, never been exposed to the dangers of free ranging. They’ve been carefully bred with the aid of some of the best genetic science available. They’ve been kept in well ventilated and pest free environment providing clean water and constant access to commercial feed. If they are lucky they might just struggle to 4 years old, finally succumbing to one of the cancers common to high production hens.
View attachment 3202599
On the other hand here is a pair of dirt scrabbling mutts who have eaten everything from mice to Orkney mature cheddar cheese. Every day they risk predation by free ranging. Given a choice they’ll drink from a muddy puddle. No scientist has improved their health with careful breeding, special diets and ideal keeping conditions. If they can dodge the predators and keep out of fights they may live to ten, or twelve years old.
View attachment 3202600
How you keep your chickens is your choice; unfortunately for the chicken.