Because I live in remote Alberta, and the UFA was closed today, I could only get 16% poultry feed. It said, on the bill board, 16% RTN (rationer). I have 10 week old ducklings. Will this work satisfactorily? It doesn't say what the niacin content is, as it's feed store-mixed. They had chicken scratch, turkey starter, poultry rtn, chicken layer. So is the poultry rtn all purpose for all poultry or will my ducks need more niacin? What contains niacin besides brewer's yeast and niacin tablets?