I used to have to two plastic composter bins, because I decided to give it a try. After about a month, my chicken stopped laying, at least in her nest box. But I could not find her eggs any where. I had not really checked my composters for a long time, because i forgot about them (OOPS) :). So I...
I feed my birds scraps too, and they seem pretty healthy. I don't think that scraps really hurt birds, as long as its not a great deal of junk food or anything.
My guinea fowl do love french fries though, and cheese puffs, but that's a once a year thing. :)