Hey Kevin565, thank you for responding. So I am dissolving between 250-500mg of niacin into 1 gallon of water- multiple times a day. I also put about 2-3 tbls of yeast into their crumbles. I started out with a brand called Duram, then purina, and now I'm on a wild game feed which I'm unsure of the brand cause I am not home right now. I ordered mazuri from my feed store.
My personal suggestions would be to:
Cut back the niacin levels to 100-150 MG per gallon of water.
I would suggest adding in a broad spectrum multivitamin. You'll want one that doesn't contain iron in it.
It also wouldn't be a bad idea to see if supplementing vitamin e improves their condition.
Is there any possible way they could have gotten in to something toxic?