Hi, I have 6 new ducklings that I purchased ant Rule King this year 2 Khaki Campbell’s, 2 Rouen’s, and 2 Pekin’s. They all seem to be just fine except for one of the Pekin’s, for some reason it seems to have a niacin deficiency. Is this something more common for Pekin’s? iv put them all on vitamins powder for poultry and they all eat starter feed. I’m planning on getting the 100 mg to 150 mg niacin. Do I need to separate the Pekin’s from the others, or should I just give them all niacin? Iv read that to much niacin isn’t good and can cause kidney failure.