If you are planning on getting ducklings, don't feed them layer feed until they actually start laying. It doesn't have enough protein for growing ducks and too much calcium. If you do give chick feed make sure you add extra niacin. Many folks, including myself, prefer to use brewers yeast for that. There is a lot of info here on BYC regarding where to find it and the dosage. In an ideal world, growing ducklings require different amounts of protein as they age. I find it much easier to feed all my birds Flock Raiser with 20% protein for all stages of life. I don't give treats for the first few weeks so they get enough protein. So far this is working very well.Can ducks eat hen layer? That’s what I plan to feed my ducks when I get them come spring. Also any thoughts on ducks and chickens living together? I also have a rooster.
As for housing chickens and ducks together, for some people it works and for others it doesn't. I house my chickens and ducks together in the barn. They free range all day. I haven't had any serious problems. There have been the occasional peeking or chasing but it's never serious and seems to be normal hierarchy stuff. There is plenty of room for those getting pecked to get away and out of sight/reach.