Great info people (Duck_Feeder). I had not given any supplaments because it has it in the flock starter food and my duckies have been free ranging every sunny day since week 1 1/2. They LOVE the chard growing in the garden, good thing I don't like it myself. I guess I will add some brewers yeast since we already have it for the dog food (helps deter fleas) if they show any signs of limping or whatnot.