Breed identification help

[Ihavens]

Can anyone tell me what breed of broiler this is? They’re growing relatively slowly, the pictured bird is about 12 weeks old. I’m beginning to think that maybe they aren’t broilers. Some of them have more black on their tail feathers and around the neck.

Thank you!

 

[Molpet]

My 12 wks CX

 

[Ihavens]

My 12 wks CX

Ok. So probably CX, they’re just not very plump and they can run fast, I was always under the impression that CX have leg and weight issues and grow super fast.