Feed your ducks with rations formlated for them.
There are 3 duck chows: Starter (20% protein), Grower (16%) and Breeder (17%).
There is no maintenance feed. The Purina spokesperson in Missouri suggests just keeping them on grower, except during breeding season.
Duck chow is apparently not available in all parts of the country, at least not all 3 types. The spokesperson said to please call them in Missouri and tell them where you live. They will then tell you who your Purina dealers are and what they can and cannot get. If anyone is having trouble getting any Purina product from any Purina dealer, they will talk to the dealer, if the dealer is able to get the product, but simply doesn't want to. The phone number in Missouri is: 1-800-227-8941.
You can also e-mail them at their web site: Purina-Mills That site will soon be getting a poultry link, according to the spokesperson.
Purina's Mazuri line also has 3 waterfowl products: Starter (20% protein), Breeder (17%) and Maintenance (14%). This is top of the line feed that even floats!
It costs over twice as much as duck chow. Mazuri feed is made only at the Purina plant in Indiana, and all Purina dealers can get all Mazuri products. Their web site is here: Mazuri It's a really neat site that tells you everything about all Mazuri products.
Thanks to GooseGirl4Ever for sharing this information.