So far since I have let my 4 girls free range in my moderate sized backyard all day they eat very little of the feed I mix for them. I also give them treats (sunflowers) and other table scraps. For the most part they seem to prefer the garden greens (broccoli leaves, beat leaves, etc), tomatoes, and hamburger. We have to fence the garden until we are done with a crop just to keep them from devouring everything in their path like locusts. They are not laying yet but them seem healthy and happy, so we will have to see what their production is like when they do. We have a lot of weeds in the backyard so I am debating putting down some seeds and growing barley and/or wheat grass for them to munch on. Has to beat the weeds.
See hearts34's post above.