My wyandotte hen has been laying very thin eggs that literally feel like sand paper. They are so thin and delicate that even my finger can break these eggs with the slightest pressure. I know that feed is most likely contributing to it, but no matter what feed I change to, it persists. I do put in oyster shells with the feed and even have the Nutrena layer feed that is supposed to help with shell thickness, and still nothing. She isn't an old hen, maybe about a year old, and when she was free range in the summer months her egg shells were beautiful and thick. Any solutions or tips? I was gifted an awesome incubator for Xmas but none of her eggs have survived past a few days, I am certain it is due to the condition of the shells.