I know that you're supposed to supplement regular chick starter with niacin for ducklings, because they require much more than chicks. So I am feeding them flock raiser right now, but since they seemed to be a little weak in their legs I started sprinkling about 125 mg of niacin on their feed(I have twelve ducklings). They seemed to be doing better, but I wanted to know if it was safe to feed them more or whether I could just set a little dish of niacin in their pen or not. I'd like to make sure they have as much as they need, but I don't want to harm them. Does anyone have suggestions?