Chickens stopped laying, only occasional wrinkled eggs.

[splady]

My 5 adult chickens have stopped laying. We've had two eggs in 4 days which both had wrinkled shells.

We recently introduced a silkie cockrel, 8 chicks and one teenage chicken to the flock.
The chicks have been in an ark sharing a garden with the adults so they all know eachother but the silkie is new to everyone.
The chicks sleep in a big cage in the chicken shed and spend their days in the ark with the adults outside so there hasn't been much opportunity to establish a pecking order, we were worried that they were too young and couldn't handle the attack.

I read the wrinkled shells may be due to a calcium deficiency but i wondered if that could be caused by stress too?
We feed them their own egg shells usually but since they stopped laying we haven't had any. I gave them milky porridge this morning.
What should i do?!

 

[HEChicken]

How old are they? It could be stress from the introduction of the new birds or something else. Did you quarantine the new ones before adding them to the flock?

 

[splady]

They're about 2 years old, not too sure as they were rescue hens.
The chicks were all hatched here and they're disease free.
The rooster wasn't quarantined though, could he have made them all ill?

 

[Echobabe]

My production is way down--dried up really. 5 hens and I'm lucky to get 1-2 eggs a day, and one I already have to toss due to antibiotic withdrawal. Maybe the extreme heat we had is behind it.

 

[RHRanch]

What do you feed as a ration? Does it have oyster shell? How many eggs had you been getting before production stopped?

 

[splady]

Each chicken was laying 6 eggs a week so we usually had four eggs a day.
We feed them kitchen scraps and porridge. They rummage around in the compost bin and the garden and get what they want from there too. They also get grain buti don't know what kind.
We're ordering oyster shell for them now.
Thanks for the replies so far!

 

[splady]

The chickens seem to be sitting in the nesting boxes a lot but we still haven't had any eggs. They quite often sit there for the whole day. Any ideas?
Also one of them seems to have a cold. I picked her up this morning and she was wheezing. Could being ill stop them laying?