Little duckling not doing great

[mule ears]

10 ducklings just arrived and 1 little guys not looking so great hes on the runty side as well as missing some fluff on his neck and by his little wing (getting pecked/trampled?) seems in good spirits but is having trouble with one leg doesnt quite look like splay leg but maybe It is. Looking for advice on the leg and the bald patches and overall duckling health. He can use one leg pretty good but the other not at all so leans and wobbles and mostly lies down. No visible injuries on the leg. I'll attach pictures have a video but cant attach it. I have already added niacin to the food but can I add too much? Also can I give him some cooked egg like you can give a little chick who is struggling? Thanks for the help

 

[Isaac 0]

A video would be great as there are a few problems that may look like a niacin deficiency but really aren't. Upload your video to Youtube or Vimeo and then copy/paste the link here.

 

[mule ears]

A video would be great as there are a few problems that may look like a niacin deficiency but really aren't. Upload your video to Youtube or Vimeo and then copy/paste the link here.

One video of a very mad duckling. he does at least seem to be in good spirits. and I attached a couple more photos

 

[Isaac 0]

How does his leg feel, warm?

 

[mule ears]

How does his leg feel, warm?

The legs are warm but about the same as his body dont seem overly warm. They also feel the same on both legs