Consistently thin egg shells in 2 year old hen

[CathyB59]

I have a 2 year old barred rock hen who lays thin shelled eggs. Almost every day her egg is either cracked or broken (usually just cracked). She has calcium (oyster shell and recycled egg shells) available 24/7. In spite of having the appropriate feed when she was growing, I think she must have had a calcium or Vitamin D deficiency, because she has always laid thin shelled eggs. Is there any way to add extra calcium to the feed other than having it available free-choice or maybe a type of feed that has extra calcium already added? She is one of my best egg layers, so I would hate to have to cull her just because of this, but I'm afraid that she or one of my other chickens will discover her broken eggs and decide to eat it and become an egg-eater.

Thanks for your help.

 

[steelchair]

Is she on a layer feed ration? Do you have hard bottom nest boxes? Maybe add more nesting materials if you are getting cracked eggs.