Chicken lying down, head tucked in feathers

[chickenbaguette]

One of my Columbian Blacktail hens, Normal, has started to lie down on her tummy with her head tucked round into her feathers. She never used to lie down except with the others in the shade to preen, was always following me around.

Here she is, before this started:

And lying down as I described:

She does this in broad daylight, not going to sleep or anything. It's not cold at all here, usually around 18 degrees C.

The only other thing is I've noticed there seems to be a bulge coming out of her vent when it's relaxed, but couldn't get a picture of it. It holds it open, but when I look it seems completely normal. I might be imagining it.
She also seems slightly off her food, but not overly.
Otherwise she's perfectly healthy.

I have no idea whether she's vaccinated against Marek's, but it's likely since she used to be one of the hens laying for Waitrose.
I'd guess she's around three years old.

So, is this something to worry about?


Also, smears of what look like blood have been appearing on the eggs of another of the Blacktails. What can cause this? They seem to have gone now, but started about a month ago and went on for quite a while. I could see nothing wrong with the chicken.

 

[CapricornFarm]

It might be wry neck, though generally you see it in younger birds. It won't hurt to treat her for it. Use polyvisol(baby vitamins) without iron. Open a capsule of vitamin e and give her that. The blood on the eggs happens sometimes when they are laying. Don't know if there is anything you can do for that. Maybe add some vegetable oil to their diet ? Good luck.

 

[chickenbaguette]

Thank you! It could be wry neck, but it's not fixed. They sound like good vitamins to have anyway, so I'll see if I can get them.