Nutritious feed for ducks
- Overrun with Runners
There is a sticky on the Ultimate List of Duck Treats - link at the top of the Duck Forum index.
Generally, you can find waterfowl feed or poultry feed that will do pretty well, and adding some fresh vegetables like lettuce and peas - but as a smaller portion of their diet.
There are suggestions for feeding from what you can grow on a homestead at Mother Earth News.