I use an all flock. can't advise on the other, but my flock of Muscovy's my chickens and my geese eat Purina Flock Raiser.I have some full grown muscovy ducks. I feed my chickens nutrena naturewise layer and feather fixer mix. Should I feed the ducks all flock or feather fixer? They both have 18% protein. My ducks are for eggs not meat.