I've seen it done on a large scale, and the resulting damage was staggering. I visited a bird farm that recieved donated old bread...it was dumped into plastic trash cans and fed to the birds in an effort to save on feed. Well, the end result of feeding too much bread, and not enough chicken feed alone was enough to nearly put the farm under...then add the mold that started to grow and the bread continued to be fed. Well, the end result, a whole barn of breeding pens with sick, and dying birds. I'm sure that birds get some mold, not to mention many other things they should not eat from time to time, but why add to thier own bad choices by offering up one of your own? I say stick with air popped pop-corn(aka chicken crack) as a healthy treat. HTH