Small chick

[kattabelly]

Do you think its could possibly be coccidiosi? Ive had them on medicated chick fed since I got them, and here poops look normal to me but being lethargic, not growing and kind of unkept look has me thinking maybe? Should I give them all corid incase?

I'd be pretty surprised, since this started at only a few days old, unless they'd been exposed to a really huge amount of coccidia - soil from a very densely stocked chicken run in a warm, damp climate, or something like that.

 

[BDutch]

Are they smaller than bantam Australorps?

Their weight is not very different.
From the internet:

The standard Australorp bantam rooster weighs approximately 1050 grams and the hen approximately 950 grams.

The Amrock Bantam (European descendent from Plymouth rock) rooster weighs approximately 1000 grams and the hen approximately 900 grams.

My Amrocks are over 1 kg and too heavy for the standard.

 

[kattabelly]

Their weight is not very different.
From the internet:

The standard Australorp bantam rooster weighs approximately 1050 grams and the hen approximately 950 grams.

The Amrock Bantam (European descendent from Plymouth rock) rooster weighs approximately 1000 grams and the hen approximately 900 grams.

My Amrocks are over 1 kg and too heavy for the standard.

Are those the Dutch breed standards?

 

[McChooky]

Their weight is not very different.
From the internet:

The standard Australorp bantam rooster weighs approximately 1050 grams and the hen approximately 950 grams.

The Amrock Bantam (European descendent from Plymouth rock) rooster weighs approximately 1000 grams and the hen approximately 900 grams.

My Amrocks are over 1 kg and too heavy for the standard.

I have 2 dominiques and 1 barred rock and all 3 are the same size. They came drop shipped from a different hatchery than the one I placed my order with so I don't have a clue where they came from

 

[BDutch]

Are those the Dutch breed standards?

The Amrock hen 900 grams is the Dutch standard. I’m not absolutely sure about the Australorp bc the website where info on standards from all breeds was collected, no longer exists. The info is AI generated. Wikipedia and the site of Australorp club dont give the standard weight for bantams.
I suspect the weight-info comes from another country. Probably Germany, bc the bantam Australorp in Europe is established there.