the cheap 3 grain scratch and the cheap wild bird seed, i would not risk feeding it to my birds. i use southern states poultry feeds. they have 5 and 7 grain scratch feeds with whole corn and whole popcorn, wheat, milo, red milo ... this is not a treat but can be fed everyday. i like mixing the rockin rooster scratch with layer pellets and oyster shell. in the fall when moulting, i feed them whole corn, sorghum, sunflower seeds and turnip greens. in late dec to january, when breeding season is about to start, i use the rockin rooster scratch. summer they get a lot of garden scraps. the rest of the time it is the layer pellets or pellet, scratch, oyster shell.
She has been using these for years in lieu of shell grit, and reports no bad side effects. 