I have a satin silkie hen who is 10 months old. She has been laying for a few months. Her eggs were always oblong in shape, but recently they are flattened on one or both sides and they have ridges/rough areas on them. She lays several times a week, and every egg I have got from her in the last month or more has looked similar to this. They are normal size for her, and the shell is thick with normal contents. I feed Purina flock-raiser crumble and offer oyster shell separately (since I have roosters and non-layers in my flock also), as well as 5-grain scratch for treats. Any idea what could be causing this and what I can do to “fix” it?