Is it possible for chickens to get too much calcium? I buy the Purine layer crumbles with oyster shells. In addition, I give them free access to their own shells separately. Does it look like this is the result of too much calcium or just how a particular hen's eggs look? One hen always lays the speckled kind on the left. And I think another hen always lays ones that look like the one on the right. I just thought it was a lighter egg, but it looks likes it's just more spotted. Thanks for any input you can give!