We started with Turkey-Watefowl starter crumbles, 27% protein, so I added one part chopped rolled oats to four parts crumbles. At 2 weeks, we started mixing in grower pellets little by little into the starter crumble. So each day I would add just a little more grower, till it was all grower and we had used up the starter. About a month before they began to lay (when they started playing hop on top), I set out free choice oyster shell. Eventually I switched over to layer feed with free choice oyster shell. Right now I feed layer year 'round because some of my Runners seem to need extra calcium. I also supplement as needed with calcium citrate solution, about 50 mg per duck per day, more or less. And that is due to soft eggs. When I give the Ca citrate, all the egg shells are normal.