Roo with a wing situation, not sure of the cause

[Aunt Angus]

I've heard it's a vitamin deficiency in Waterfowl too. I was digging into the cause of angel wing a few years ago when I was raising guineas.

I'm not totally sure what vitamin, but it doesn't hurt to go broad.

I had read otherwise for waterfowl. I'll look into it more, myself. If it's diet related, it should be avoidable/correctable right?

Thanks again!