At our urban-farm, we let our chickens roam around foraging all types of vegetation, small critters, and scratching up the earth. 

Pastured chicken eggs have been found to be up to 700% more nutritious than supermarket-bought, industrialized chicken eggs!

Another added bonus to allowing chickens to behave how they were created to behave, is fertalizer.  You know what we mean... without going into further detail.  They provide one of the most potent sources of natural nitrogen, as well as many other helpful healthy soil-makers.

Often times industrialized chickens have unclean living spaces, and that is typically rectified by the use of antibiotics, drugs, and other chemicals. We don't use any of that, while maintaining a much cleaner, safer, ethical living space for our birds.