Thanks for the good news. I was a bit bummed with the numbers in the book. I did some more research and found an article with two key pieces of information.

http://www.countrysidemag.com/issues/90/90-3/Jim_Hogue.html

The article is about Carl Hammer in Montpelier, VT who raises 1,400 chickens on primarily restaurant garbage! Even better, was the method for protecting his free range flock from predators. He relies on a single German Shepard.

One fact I have not found yet is the ratio of birds to acres during the spring, summer, and fall that allows for enough forage food that supplemental commercial food is not needed. I'm sure that ratio has a wide variation depending on the makeup of the land. Lawn, hay meadow, meadow no longer hayed and left to grow, shrub growth area, and forest area.

On another note, back in the seventies when we raised a couple of pigs we feed them primarily with day old donuts from Dunkin Donuts in Essex, Jct, VT. We typically picked up two to three bags a day. If I remember correctly, the bags were about 3' tall. I also remember eating quite a few before they got to the pigs:)