[SLI]

Could anyone give some advice please? I have 4 Orpingtons and they were laying really well up until about 4 weeks ago. One of the girls always has a bald breast and I thought that she pulled them out herself, but now another one has a bald breast. Whenever we have a good downpour one of the girls seems to get a cough (not always the same bird) and now they seem to be not laying. I was getting maybe one egg a day and for the last week nothing at all.
I use shavings and straw in their shed & there is no sign of mites or lice. They eat well ( organic layers pellets) and have a handful of organic mixed corn in the late afternoon. I use cider vinegar in their water, garlic granules and poultry spice in their feed and the shed is cleaned regularly. Every week all of the shavings and straw is swept out and slung in the compost and new put down. I also rake out the run and they roam around the garden freely when I'm at home. 

[manian]

not sure about the cough.
are they showing signs of being broody the breast goes very hot when becoming broody and they clear their breast feathers
Mx

[Bright Raven]

Do they feel hollow or thin around the chest, are they loosing weight or condition?
How old are the birds?
Where did they come from? Could you ask if the breeder has any others with this problem at the moment?

Additional vitamins may help. There is a children's vitamin product called Abidec, a few squirts in the water might help.

I had a similar problem with Barnvelders years ago and lost a breeding trio from a local breeder. They had the same problem as yours but with the additional symptoms above.

I hope they are perking up for you, you seem to be giving them the best care they could have.
Don't blame yourself, sometimes rare breeds and fancy hens are a bit deficient with immunity due to close breeding and matching.

Another thought.... Do you have good ventilation in the coop? They need a bit of air flow.

[jaykay]

I'm guessing they're about to moult or go broody - half my flock seems to be doing one or the other and therefore have stopped laying 

Coughing might wel be worms - when were they last done?

If recently, then maybe a respiratory infection in which case you'll need to talk to the vet and get an antibiotic like Tylan. And personally I prefer to inject or drench rather than try to give things in water or feed.

[SLI]

Thanks for the replies. They are due for worming, although I don't really think it's that - don't know why! Today theyve been wandering around the garden and Gladys my silver birchen laid an egg and Gracie my splash has left feathers strewn everywhere so maybe they are moulting....
The girls were POL when I got them so I'm guessing they're about 18 months old. The other two seem fine which is a bit weird.
The shed where they're kept was new when I got the hens last Easter and is open all day and when I shut the door at night there are large ventilation holes at the back - and only these two of the four are showing these symptoms. Their combs look nice and red and perky too.
Thanks again for all the replies. I'll worm them tomorrow and wait and see