Why are my chicks growing at different rates?

[Gypsy07]

So I hatched out three different batches of chicks recently. Not only are they all the same breed, but all the eggs also came from the one hen. The first bunch (5) are two weeks older than the middle lot (3), who are in turn two weeks older than the youngest lot (4). So they are roughly 9, 7 and 5 weeks old. The oldest ones are massive. When I put the middle ones outside with them ( a couple of weeks ago) they looked tiny, but I thought it was just one of those comparison things. But then a couple of days ago I put the youngest ones outside too, and they're easily the same size as the middle ones, maybe even slightly bigger.

So what's going on? They were all incubated, brooded, fed and reared pretty much the same way.

Why would the middle three be growing more slowly than the other two groups?

I don't think it's a pullet/roo thing, as out of the first group, the biggest is a pullet and the smallest is a roo. The middle three are all pullets, but in the smallest group there is at least one pullet the same size as them...

Anyone got an explanation?

 

[tryingtohaveitall]

Curious to hear answers...

 

[Gypsy07]

You and me both!!!

 

[BarefootMom]

every animal and (humans) are different!!

I have 2 kids-- a boy and a girl

My son weighed 9lbs 10 ozs and was 25 inches long at birth--now he is 3 1/2 and the size of a 5 year old

My girl weighed 6lbs and 6 ozs and was only 18 inches at birth-- now she is almost 2 and the size of a 2yr old

I didn't do anything different with them, they have the same father (and mother haha)

one has thick curly hair the other has thin stringy hair

their personalities are complete opposites

I think it is the same with the chicks, everyone is different.

 

[ranchhand]

Hi Gypsy!

I don't have any easy answers for you, but the first thing that occurred to me was perhaps a slight difference in incubation. Or, same hen, but is it for sure the same rooster in each case?