moscovy Ducks strength legs

[henny12]

A few years ago I had some baby moscovy ducks and read somewhere that if I fed them________ vitamin/mineral crushed in their food it strengthed their legs. I cannot remember what. It worked when I used it, but haven't had babies for a long time until now. I think it was niacin or B 12 or what? Can anyone help. It was listed in a forum like this. Henny