A while back I received some great advice on this site when I needed to improve my ducks health. It was recommend`ed to give my ducks a good quality Cat kibbles or Dog Kibbles, grain free, but good protein as a treat. So I did get a bag of Kitten Kibbles at Costco.
Comparing the price and comparing the ingredient`s, especially niacin . And they love it. It is not cheap either.
I ordered a big bag of Organic feed on Amazon, but was disappointed, seeing it falling apart with moisture in the air. Ducks eat any thing and every thing but I do not want fish products because the eggs will taste fishy.