What can you feed the swans apart from bread?

i believe so but sometime u do not want to force them to eat it but i think they do like bread. I think that u have to give them a certain type of bread but u don't want to always give them it cuz then if u keep giving them it they will get used to it and when u stop their not going to be able to find food on their own, AND THEY WILL DIE. U could feed the once in a while but not all the time.