I use oyster shell free choice. Egg shells are fine, but it takes so many that supplemental oyster shell is really necessary. They really need a lot of calcium every day. I don't use layer feed because I have some youngsters and roos in with the girls. a couple of days ago I flaked and let their oyster shell run out. The next day's eggs were misshapen and wrinkled. I ran right out and replenished the oyster shell. The next day, the eggs were fine, with no sign that anything had ever been wrong.
