So after reading your responses and others discussing chicken nutrition, I have come to a conclusion. The best premium chicken feeds are evolved to be the most nutritious and healthy formula for laying chickens. Free range is great, but leaves the decision of what to eat up to the chickens. I think chickens are very curious eaters and will eat what ever looks interesting to them. This may or may not be completely healthy. Logically, one might argue that chickens like most other species have evolved over the millennia to seek out a diet that maximizes health and reproduction based on anatomy, and resources available.
So for example carnivores have teeth that are designed to rip and shred while herbivores are better designed for mastication (chewing) such as cows and horses etc. and of course omnivores can do both. But, chickens may not always make the best choices. I have seen them eat things that are quite detrimental to their health or they may just eat what they like such as bugs and/or grasses and vegetation of different sorts which while good for them may not be balanced either in protein, carbohydrates, fats, vitamins or other nutrients.
So here's the interesting thing. Most animals (to my knowledge) in nature have not evolved to have longer or healthier lives, while domesticated animals which depend on people (and people) who have diets that are scientifically formulated for longevity and good health, live longer and healthier into old age than their ancestors.
Based on this line of logic, free range chickens may not really be healthier than chickens that live in closed runs and coops and forced to eat formulated food. This assumes that in both cases, the animals are given healthy environments and access to sunshine and are able to exercise. My comparison is between healthy environment free range and healthy environment confined chickens only, not factory chickens who eat formulated feed. Also, I question that free range chickens only eat healthy bugs and veggies. I have seen them eat rotten food and food that is definitely not healthy like unhealthy or sick mice and other yucky stuff, which might have a negative effect on the egg you eat.
And as far as all the additives to make the yolks more orange or darker are not especially healthy additives. They are not unhealthy, but do not add to optimum health, they only have the goal of effecting the color of the yolk, Such as Marigolds or corn. These are fine but not significantly adding to the health of the chicken or their eggs. Chickens are smart enough to only eat the amount of calories they need so more food dye foods equal less nutritious foods. I think my chickens with their average bright yellow yolks are probably healthier than most dark colored eggs where the chickens are eating carotenoids for color instead of the most balanced nutrition offered in their store bought feed.
That is sorta how I feel.
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