Hello, I recently got my first duck babies and they are about 9 weeks old this week. I have been giving them Brewer's Yeast every day since I got them and I was wondering how long I need to supplement Niacin in their diet? I heard that they'll only need it until about 10 weeks? Also, how many weeks old should they be until I start feeding them Flock Raiser? Right now they are getting a 15% pretein feed because I read they need less protein while they are growing to prevent Angel Wing. I am new to this and want the very best for my babies so I hope someone can help! I appreciate it very much!