I have just stumbled across a thread saying the extra calcium isn't good for the drakes. Is the layer feed a no no for the boys? If I leave a dish of oyster shell for my girl, will the boy know enough to not dip in? Lucky is almost 7 months old, and I'm hoping for her first egg soon. I want her to be healthy, but my drake too. Right noe they are on a mix of flight maintenence and cracked corn.