I get frustrated at the 'nutritional information' (or lack of) on packs too. But if it says Brewers Yeast then it's full of the good stuff.
Hope your babies continue to do well. Feel free to post a photo on the Duck forum. Everybody loves seeing those little cuties.
Does brewers yeast contain niacin?
General. The B-complex vitamins in brewer's yeast include B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyridoxine), B9 (folic acid), and H or B7 (biotin). ... Brewer's yeast does not contain vitamin B12, an essential vitamin found in...