Why is my chicken not growing

[EmmaRainboe]

OP said amrock and a golden comet were the parents.

I asked for photos of said parents.

 

[SilverBirds]

I asked for photos of said parents.

Gotcha. Guess I read to fast because I missed that part.

 

[EmmaRainboe]

Gotcha. Guess I read to fast because I missed that part.

No worries

 

[Nija Chick]

I would say off hand that one of the parents isn't as purebred to specific species as you were led to believe. That unfortunately happens a lot, if you originally got the parents or grandparents from a hatchery.
There's also the visiting roo possibility to consider.

chicken genetics are fun and full of surprises. Unless you have a clinically sealed pens inside where no outside visiting is possible.

Off topic of the little guy's breeding, I'm happy to see they are free ranged a bit at least. They get most of their nutrition there.

People have been led astray to think that corn is just fine for chickens to eat, so many companies put it in everything, even carnivore diets, like dogs and cats.
But it truly is actually damaging to chickens (and other pets) health. It's like candy to them but they can actually starve to death if that's all the bird wants to eat.
If it's saving money on feed that you want, your much better off getting a bag of wheat groats, or oat groats.( whole kernal with bran intact) that is just as cheap. And forgo corn that will actually takes up space, and prevents nutritional uptake. It's truly almost as bad as filling up with plastic.

Your little guy is adorable anyway. I have many mixed breeds that hatch their own, and I am often left scratching my head wondering what breeding caused that look in a chicken.

Chicken math rocks