[Mildredsmum]

Hi,
I have to Warren hybrids who are about a year and a half, who I keep in a large run at night and let out to free range during the day.
Recently, one of them has been wither not laying or laying eggs with no shells. I went to collect eggs today and was stunned to find one shell-less egg in the nesting box, the "membrane" that covers the yolk and white mixed in with some faeces and then a shelled egg with a bizzare yellowish "crust" all over it on the floor in the run!
These have all come from one chicken in one day! The other chicken is laying fine.
What is causing this? I thought it may be dietary but then read that free rangers get the best chances of getting all their nutritional requirements?

[joyfull]

do they have 24 hour access to oyster shell? Free ranging gives them access to grit which is used to grind down their feed but they do also need a form of calcium. Unless you can guarantee they are getting loads of things like crushed snail shells then you do need to supplement their feed with oyster shell 

[Dominic]

I've had a couple laid with the outer sack formed, but no hard shell.
I've also had some without even the sack.

Make sure oyster shell is available, but dont mix it with the food, they seem to know when they need it.

[reidi]

I have had this before, when i kept my hens in the garden.  It seemed to be thunder that caused it as they would be there after a thunder storm but were ok again a few days later.

reidi