I bought some new hens. I got three barred rocks and two rhode islands. Well i have had them 4 days now and they are laying like crazy! I am getting an egg from each hen but most of the eggs i get are broken or cracked and the shells are very thin in some spots. I have oyster shell out for the hens to eat, but what else can i do to help get eggs i can actually be eating? Has anyone else had experiences with this? Any advice?