We have 6 mature layers and get 4 to 5 eggs a day. When we first got the girls the eggs were smooth except for 1 brown egg ,which was typically lightly sandy/ chalky. We added a dish of oyster shell, thinking the girls weren't getting enough protein. The chickens are all free range and we feed cracked corn and Purina Layena Sunfresh pellets. Yesterday, ALL the eggs except 1 were a bit sandy! What are we doing wrong? Does it matter? I also feed cottage cheese as a treat once in a great while--someone suggested that the cottage cheese is too high in protein and that is causing the sandy eggs-but the girls have only gotten cottage cheese once in the past month and they LOVE it! Thanks for your help!