a bunch of hatcheries, some in the land of OZ
https://www.feathersite.com/Poultry/BRKHatcheries.html
although this may not be up to date, I clicked on a couple which either didn't have any available or wasn't a active website
After WW II my dad was a garbage truck person and there was a local hatchery on his route. It supplied the local farmers. It's been out of business for probably 50yrs. When the hybrid layers and broilers took over the farming poultry.
Most small farms had poultry, but when the store started...