Shell-less egg in their run, what to do? (pics)

[Poliwag]

I found this shell-less egg in my chooks' run. It was still warm when I picked it up. I have no clue which chook did it. Is this bad? What should I do? What can I do?

 

[chickenzoo]

Up the calcium in the feed. Do you feed a layer or give free choice oyster shell? Sometimes shelless eggs just happen, but if it happens more look into the calcium.

 

[havi]

Never mix in the oyster shell with the feed. Just give it to them free choice.

 

[Poliwag]

I give them laying mash. It has pullets, seed and some sandy stuff that they don't seem to like.