I've been using Nutrena 'All Flock' as my duckling starter. It's 18% protein, 2.5% fat. Is that sufficient? I've heard that ducks need 20 but I've raised 7 ducks on it and they're all thriving now. I give the ducklings a vit/min/electrolyte supplement every other waterer fill up. (I also give the supplement once a week to my chickens and adult ducks.) Will having only 18% protein affect them in the long run, though? I keep them on it throughout their entire lives. They LOVE IT! I will just give oyster shell to my girls. Should I give them some ground up cat food for animal content and to boost the protein? I know it's very good for chickens but I'm not sure for ducks?