Thank you Amiga for your post! I was hoping you'd comment, since you're super knowledgeable about duck injuries and such.
I didn't know niacin deficiencies could cause neurological problems! Though I guess that makes sense, considering it does effect legs.
I just want to add that adding iron is not good for ducks. It will kill them. I don't know about molasses, though.
Also keep in mind that this stuff doesn't help immediately. When my duckling had a vitamin deficiency, it took a week before we were able to really notice a change, and another...