I have fed oyster shells, spinach and egg shells. The eggs are still weak from my 2 year old Barred Rock.
I have actually padded the bottom of the nesting box since I heard she may be standing up to lay her eggs. Regardless, the eggs are thin and cracked every day. She lays 5 times a week and they are all thin.
She does free range and I do give her garden and table scraps. She is on 16% feeder pellets.
My younger hens have started laying really hard shelled eggs.
I've tried it all. I'm frustrated. Help!