What has happened to my egg?

[Birtles]

Any idea what form of 'stress' has caused this to happen. These are all today's eggs and I had the same thing happen from this chicken yesterday as well

 

[mmclaughlin]

I have a hen who lays this egg all the time..not sure why they all have oyster shell available all day long she eats the same as the rest....
I can't help identify the reason but maybe someone can!!
otherwise my hen is healthy and friendly!!

 

[Birtles]

Other than the unsightly appearance, there's nothing wrong with the shell. Its hard, firm and strong and appears just as solid as any other egg with no weaknesses.

 

[mmclaughlin]

mine is a little thin ...and an a bit large... but egg looks great on the inside lol!!