Hi, I know this post is several years old at this point, but I thought I'd put my experience with the Kalmbach pellet feed in case anyone wanders across it and wants more info.
I've been feeding my flock of ducks this feed, once they're off the starter feed, and they do well. I do cut it with ~25% oats to lower the protein amount and they free range nearly everyday. I also give them bugs when I go in to swap their water so they aren't so timid around me.
Recently, we had to cull one of our birds (they're dual purpose breeds so instead of being a vet bill, they're dinner) due to a leg issue that I think might have been an infection (the leg was swollen for a bit, which i thought was just a sprain, but then it started getting hot). We culled her before it got worse and spread, but I think it might have stemmed from a niacin deficiency, so we started adding brewer's yeast to their feed as well.