@Danish aseels can you get brewers yeast or nutritional yeast both can give your duckling the niacin it needs for health and protect those little legs.
Only problem I see is it being time released which I know we shouldn't give plain niacin to our birds if time released because it doesn't work like reg niacin that isn't time release of flush free so maybe best to try to find one that isn't time released. Sorry I should have said this in the...