We feed our goslings and ducklings Mazuri Waterfowl Feed plus Purina Flock raiser or we look for a feed (such as broiler or game bird feed) which has a higher niacin content. The niacin is important for their leg strength. Later we start adding grains to their feed to reduce the protein content and by the time they are adults they receive a mix of equal parts of Flock Raiser, Recleaned Red Wheat, Whole cleaned Oats, and Mazuri Waterfowl Maintenance Feed. The Mazuri feeds float so they can be fed on the water.... the ducks and geese go nuts when we throw it in their pools.
Lower protein and niacin are both important to avoid angel wing and weak legs. If we have a duck that gets weak legs, we buy niacin at the health food store and add some to their feed or water for a couple weeks.
Chel