Molt, or worse?

[AndrewP07]

Hello, so this spring we moved onto a property where they left 9 chickens for us. No idea of age, but we were getting 9 eggs a day. We brought our flock in, who was also laying a good amount of eggs, and with a total of 27 hens, we’ve only been getting like 18 eggs a day in the summer. Anyways, the chickens that came with the property have always been really slim, and missing feathers. Here’s a pic. How do I get them back to their original plump form?

 

[Wyorp Rock]

Can you post some photos of the whole bird? Without the saddle to or at least what's under the saddle.

What do you feed?
What breed?

How many roosters do you have?
From the photo, the hen has been bred quite a bit and shows damage from breeding and feather picking.

Some breeds are slim, so it's hard to know if they are supposed to be or not. Watch to see if they are being bullied/kept from feeders, if so, then add more feeders.

How much space do you have for 36 birds? Photos of housing?

Feed a nutritionally balanced poultry feed. Look these birds over for lice/mites. Get a fecal float to see if they need deworming.