Well here's what I have and they all forage well. I only feed about 1 gallon of feed in the morning and about that before dark to make sure they have the protein and such they need. I have 20 chickens and 9 ducks, all are healthy.
ETA: 9/27/13 Since last year we revised our feeding a bit. Our Barred Rocks definitely forage the best. We are up to 28 chickens, 8 ducks, and 2 geese. I feed about 5 -6 cups of feed in the morning and free range.
Ancona - gone
Buff Orpington - gone
Dominique - gone
Production Reds - gone
Red sex link
Before starting out , I researched chicken breeds as much as possible. I looked at Dark Cornish, Black Javas, and Speckled Sussex. These seemed to meet my requirements: A) Meat bird, B)Dual purpose bird w/ emphasis on meat production, C) Good foraging capabilities, D) Hens would raise chicks.
The Black Javas were my first choice, but they are difficult to find, and the few I did find were expensive. Dark Cornish were my next choice,until I saw how pretty the Speckled Sussex were! They were simply gorgeous! It's not like me to be swayed by such sentimentality, but what can I say? JA
My Buckeyes forage well, just like Jeff said. For strictly laying birds that forage, our Hamburgs are probably the most aggressive foragers I have. They seem to eat barely anything out of the feeder and range widely as long as they can stay in the shelter of tall weeds or brush. They're about the closest thing I've seen to wild chickens. Of course they don't get very big, so I wouldn't consider them dual purpose, but if you want independent chickens that lay white eggs on hardly any food, they're hard to beat. Low maintenance, low overhead.
My Speckled Sussex are hands down the best foragers out of my group, and their coloring provides excellent camouflage. They aren't nervous birds either - they're quite curious. My Buff Orpingtons, Easter Eggers, Barred Rocks, and SL Wyandottes are decent foragers as well, but it's always the Sussex that wander the furthest.
Thanks everyone! Unfortunately due to molting and a Red Star that likes to pick feathers, my Sussex girls aren't too pretty these days, except for one. When they have ALL their feathers they are truly gorgeous birds, and they have fun personalities.
I've had all kinds of breeds over the years and I have found that my Speckled Sussex are the best foragers. There is a reason that they were THE bird to have in the days before commercial chicken factories.
Leghorns, American Games, Dominique, Buff Rocks and Sussex have all been great foragers for me. Having good foragers out with the lazy ones will sometimes encourage them to go out more. Buckeyes and Games are very alert hawk watchers.