They should be fine for the most part. I've read that fowl doesn't contain as much calcium as a rodent, but I'm not sure about the requirements of a Ball to begin with, so you may be okay there. Also, I've read complaints about the snake stool being runny supposedly from the lack of hair that would normally bind it together.

With that said, I wouldn't switch simply because a Balls normal diet consists solely of rodents. I don't think enough data has been gathered to determine the long term health affects of changing that diet to other animals like quail.