I have a dozen Blue Magpie ducks that are going on 2 months old. They are at this point making more of a mess with their starter feed than I think they are eating. I am ready to switch them but I am having some trouble figuring out if I switch them to Poultry Grower or Gamebird Grower.....The gamebird grower I buy for my turkeys says it is for turkeys and heavy breed gamebird. Does a duck fall into that? Or since they will be laying, do I do poultry until they get layer feed? along the same lines...if I keep a mixed flock--males and females....can I keep them on a set feed and just add a bowl of oyster for the layers? Thanks!