I have 7 chickens, of which six are laying regularly. Of the six, one is laying eggs with a soft shell. I think it is my cuckoo maran, but not 100% sure. By soft shell, let me explain. It doesn't look soft, or feel soft when I hold it. Its just when I try to crack it open to cook it (with a knife for instance), and it doesn't quite crack cleanly. The shell and the inner thin layer (not sure what it is called), tend to stick together a bit, and egg shell gets in my egg! What could be causing this? Same diet for all chickens, but just one seems to be this way. Any thoughts or advice? Thanks.