Yes, some research suggests that too much protein can cause angel wing or other abnormal growth anomalies. Therefore, we would suggest using only a mixture of cracked corn and poultry layer pellets as well as plenty of lettuce. Starter food can have too much protein for the young cygnets as well as some of the waterfowl maintenance diets which are usually used for adults. Even adult swans can be fed just the cracked corn and layer pellets, which will provide the necessary supplemental nutrients and filler. The Regal Swan