Last summer a college student wanted to buy some of my ducks for a food study for his schooling. He had also bought ducks from Pennsylvania. They were all Mallards. He fed them Mazuri Water fowl duck food and none of them would eat it. I bought my ducks back at the end of the summer when he was finished with his food study with them. He gave me the rest of the bag that the college had furnished him for my other ducks. None of them would touch it. I don't know why but none of mine liked it for some strange reason. He told me how much the 50 pound bag had cost and that it was supposed to be the best but my Ducks liked Purina better. How particular they can be at times, lol.