Chick isn't growing

[SunriseChickers]

We got some new chicks from Rural King last week. They are all approximately the same age, give or take a day I'd reckon.
We noticed about yesterday that the Golden Laced Wyandotte just isn't growing like the others. She's noticeably smaller, and her feathering is behind. The others started getting tail feathers two days ago, and she has none. She also has fewer wing feathers.
She isn't being picked on by the other five yet, and scratches around as she pleases.
She did have pasty butt this morning, so we took care of that, but we noticed she wasn't quite as energetic and curious as as she had been previously.
She is the one on the bottom in the picture. She is with a Buff O and a Marans here.
Any one know why she's so small and losing energy?
Her poop is normal, they have medicated feed. They are unvaccinated.

 

[JacinLarkwell]

Could be failure to thrive. Not much you can do if it is

 

[SunriseChickers]

Could be failure to thrive. Not much you can do if it is

What does that mean, like she just isn't adapting well to living here?

 

[JacinLarkwell]

What does that mean, like she just isn't adapting well to living here?

Usually it means something just isn't right with their bodies and they end up passing much earlier.

Mine tend to get to about 4 months before they just shut down, but mine seem to be kinda old for FtT chicks.

She's still very young though and might just be a bit smaller right now

 

[SunriseChickers]

Usually it means something just isn't right with their bodies and they end up passing much earlier.

Mine tend to get to about 4 months before they just shut down, but mine seem to be kinda old for FtT chicks.

She's still very young though and might just be a bit smaller right now

Huh, I see. I've never heard of that happening. So if she isn't just small, what can we keep an eye out for to know if she just won't last long?

 

[21hens-incharge]

What is the protein percentage on the chick starter you are using?

 

[SueT]

Could she be a bantam?

 

[SunriseChickers]

What is the protein percentage on the chick starter you are using?

It's 18% protein Kalmbach medicated chick starter crumbles.

 

[21hens-incharge]

Can you change to a 20% all flock or 20% chick starter?

I had one lagging behind and after a switch she showed improvement in a few days.

 

[SunriseChickers]

Can you change to a 20% all flock or 20% chick starter?

I had one lagging behind and after a switch she showed improvement in a few days.

We'll certainly look into it, thanks!