Higher CLA's - More Vitamins A & E - Higher Omega-3 - Stronger Bone Density 
We all benefit from seasonal, locally grown food and, the same applies to poultry.   Native vegetation (flowers, greens, herbs, native grasses etc..) changes with, each season and, this is nature's way of balancing nutrition for animals and, for us too.
Chickens that range freely is a potent key in raising chickens to thrive. They decide where to go, what to eat and how to forage. After all chickens have been around longer than people and, they seem to know what is best for them. 
Heritage, slow-grown chickens forage, it's what they do all day, It is their natural way of life. Feasting on nature's buffet of goodness is what gives them their good health. Ethical Chickens forage and range all day on native vegetation. They also range and hunt in organic orchards, gardens and, they follow the pigs, cattle, sheep and goats collecting grubs, catching flies, scratching for bugs and hunting many flying insects. 
Research shows that open range, pasture-raised and foraged, heritage chickens have a higher nutritional profile than the faster growing breeds fed a grain-based and, vegetarian based diets.