Caulks eggs

[Flybybirds]

Two of my maran chickens have started to lay their brown eggs with what looks like a chalky material on the outside. They have calcium free choice. It does look like a calcified residue however. Any ideas?

 

[sumi]

It sounds like calcium deposits or calcium coated eggs, but from your description I'm thinking the former. Those are caused by excess calcium in the diet, stress, or defective shell glands in the layers. More info and pics here:

https://www.backyardchickens.com/a/common-egg-quality-problems