I would be very cautious about doing so.  Ducks and Geese, if I remember correctly, don't require quite as much protien as baby chickens (depending on the breed of course).  If you are in a pinch and have to use duck/goose feed, make sure the protien is at least 18%, and no more than mid 20s.  Each feed store has their own mix, so it's really hard to just give a straight 'yes' or 'no' in this situation.  A little research on their contents would clear it up for sure!
Hope that's helpful!