Same conditions- why do I occasionally get a deformed/thin-shelled egg?

[AKnewbie]

My chickens get layer feed (inside the coop) and Flock Raiser (outside the coop).
They have a separate bowl for oyster shells.
Why do I sometimes get a deformed or thin-shelled egg?
Is this a calcium deficiency or should I look into other possible issues?

They are all Australorps, about 6months old and I get said type of egg about once every 2 weeks or so.

 

[Angelpoo]

Do they eat the oyster shells? You could also try giving them milk to eat. I think it has to do with a loss of something might not be calcium... You can find lots of info online... Anything high in calcium. My chickens don't like oyster shells so I give them lots of scraps and they free range our five acres and collect all the nutrition they need

 

[iron chicken]

how old are they?

 

[AKnewbie]

They are about 6months old.

 

[growyourbrew]

Sometimes it's the chicken themselves that lays a wrapped egg

 

[iron chicken]

usually younger hens will lay deformed eggs so it should improve with time.

 

[Hooligans7]

Do they eat the oyster shells? You could also try giving them milk to eat. I think it has to do with a loss of something might not be calcium... You can find lots of info online... Anything high in calcium. My chickens don't like oyster shells so I give them lots of scraps and they free range our five acres and collect all the nutrition they need

Here's a different one laid by one of our best layers -- check out the white speckles! What might have caused them? From an 11-month-old BR. The egg inside looked and tasted fine.