I have a small backyard flock consisting of 6 Silkies, 2 bantam Orpingtons, 2 bantam Cochins, 1 Sebright and 3 Whistling Tree Ducks. I started with only Silkies and have been feeding them Purina Starter & Grower as recommended by most Silkie breeders. Now that I have a mixed flock should I be feeding them something else? I'm not having any trouble with egg quality or shell thickness. Should I feed the ducks (who, I found out, are more closely related to geese than other ducks) something else?