I have one Leghorn, and a Wyandotte with a BRIGHT red comb (the Wyandotte also crows - and yes, she's a hen). Both tip the scales at about 11 pounds. They are very calm and placid (pets, really). I have been feeding them Layena, which is a layer crumble, and it "claims" I don't need to add anything to it... but that doesn't feel right... no grit, or oyster shells? They are roughly 17 - 18 weeks old. What can I do (if anything), to speed them along?