Have to watch the protein with ducks, I believe. You don't want it too high. Brewer's Yeast is good for any animal.Our ducks & chickens are all eating together.. Is this okay for the chickens?? When our duck hens do go broody I would like to be prepaired... We have both feed from 22% to scratch. Our local feed store also carries 28%.. They all prefer the FF, we just bought extra feed from someone, so now they have 3 different to choose from..