2 separate hatches a day apart one not growing/feathering at same rate?

[2overeasy]

Okay, first, perhaps my title is not clear but I didn't any other way to rephrase it! ;-)
So, I ordered chicks from MPC, hatched and shipped on March 26th (faverolles, orpingtons, sussex, and brahma).
Also, on March 27th/28th a broody hen hatched out 7 chicks (mixed breed, all large breeds).
So both hatches are only a day or two apart. But the MPC chicks living in the bathroom are growing big, have wing and tail feathers, practicing flying (!) and are much larger than the broody hen chicks.
I would think the broody hen chicks would be at least as big if not bigger, since they have the advantage of also foraging with mama for bugs, plants, worms, etc. They are all fed the same feed. Yet the broody hen chicks barely even have wing feathers.
This doesn't make sense. Any ideas?
Thank you!

 

[chicmom]

Well, I have quite a few chicks right now, and they all seem to grow and feather out at different rates. I've got 6 chicks that I've hatched in the incubator, and 14 chicks that I bought from a breeder, and then I have a mama that has five chicks outside.

I also have noticed the chicks with mama look smaller than the chicks that I've got in the brooder. Perhaps chicks with the mother use up more of their energy foraging. The chicks inside have it easy, their food and water is right there for them. No foraging required. So they're fat and happy.

With the 14 Silver Penciled Rock chicks I bought, they're all the same age, but I've got some with all their feathers, (they seem to be females) and the males still have fuzzy bodies, but they have wing feathers. So the pullet chicks are feathering faster than the cockerel chicks, but then the cockerels are much meatier looking than the pullets.

So, environment, male/female, breed.....they're all factors in the growing process, I would guess.

 

[cva34]

Its either Temp related or breed related.Some breeds feather faster.And chicks kept too wam feather slower..My 2C....cva34

 

[2overeasy]

Chicmom: Possible. That's as good an explanation as any. It does make sense that the hen's chicks are using their energy foraging. They have 10 acres to forage - although they only use a small fraction of it - so they do move around. And my bathroom chicks (BC) sure do have it easy! But I know the outside chicks get the same chick food and they sure do eat it!
But one thing I thought of: my bathroom chicks get treats like bread crumbs, boiled egg whites, and diced tomatoes. I'm sure that's got to contribute. I didn't think of that when I originally posted...

cva34: Temp makes sense, too. However, bathroom chicks stay warmer at a regular rate, whereas outside chicks deal with varying temps. For ex, here in Chattanooga right now, it's about 40 degrees. Outside chicks are out foraging with mama and BC are still toasty in their indoors brooder. Hm...