Niacin is just something they need more of. It should be adequate in Flock Raiser, but I had them on chick feed for a week without added niacin (I don't have brewers yeast, so I was supposed to add it to the water). Maybe it caught up with the one. Idk. I'll add it to all the duck water, and see if lazy bones perks up. There is no lethargy or anything else like that. It just doesn't stay with the others, and lays down when it does join them. It could be nothing, but if it's something it's the niacin.
How much Brewers yeast do you add to the water?
