I'm in North Central texas. The weather here fluxuates so often. We can have snow one day then 60 degrees and sunny the next. We have 3 ducks and 2 geese that free range on about half an acre. I make my own supplimental food for them and they are shiney, great weight, healthy and happy and they do lay (not now because of the temps). I mix oats, barley, sunflower seeds, lentils, corn, flaxseeds, chia seeds, dried egg shells ground down, and from time to time I add food grade DE and kelp. I also cut up our fruit and veggy scraps into small piece (no avocados as I read it is bad for them so I don't want to take the chance). All is good for them. The lady I got them from was just giving them chicken scratch. From the time I got them till now I noticed a huge difference in their health and appearance.
People regularly ask about home-mixed feeds here. Nice to read your experience!