The fact your chicken will be able to be outside, not squished together, eating bugs and things and getting real sunshine already makes them leaps and bounds better than store eggs. A balanced feed and occadional fresh greens and fruits sowill do wonders for the health of the eggs.
You will need to feed them, modern chickens are more meaty and productive, therfore require more feed than yesteryear. The best eggs come from good feed. Chickens don't really eat grass, so pasture raising really make no difference. That term doesnt even have a standard to the usda. Where are...