So how many birds are left in total?Some of my birds are 3,2 and 1 years. See we ordered 24 chicks the first year, 50 the second and 100 the 3rd (this past spring). The coyotes and foxes had a hayday this year and our egg production has gone down from 6-7 or 8 dozen a day to 1 dozen. On top of that they are molting. That being said...all egg layers or dual purpose and I can no longer tell who is who. BTW, finally got the fence secure enough, coyotes ate through our first electric fence.
So you have multiple housing so can separate while assessing?
How many do you want to remain?
Are the youngest group laying yet?
Should be fairly easy to tell the newest ones from the olders by plumage.
And you can always do butt checks before slaughter.
Slaughtering molting birds is a PITA, might as well skin them which is not easy, IMO.
Have you slaughtered before?
Do you have lots of refrigerator and freezer space?