When would be the best age to butcher these birds?

You generally want to butcher the chickens when they have reached full size, but not keep them much longer than that because you're just paying to continue to feed them and they won't get any bigger. When that time is will depend upon the type of chicken.

As far as tasting different, they should have more flavor, and I wrote a little explaining that here: http://www.betterhensandgardens.com/2011/02/27/heritage-birds-for-real-chicken-flavor/

If you're going to process them as they would have in the past, your black sexlinks would probably have been processed as fryers (they'll never really be meaty enough for roasters), and the others as roasters.

 

Your black sex links will be bigger than your Ameraucana mixes. I think the other poster got that backwards. Also as sex links, unless you got roosters specifically for meat, will be excellent layers come 20 to 24 weeks. If they're black then pullets. My black star is the best layer with largest eggs.

 

1) YES. I would wait at least 18 weeks on an Ameracauna. The longer you wait the slightly bigger they get.
2) Stick em in the fridge to rest for 1 to 3 days. I prefer 2 myself.
3 YES they will tast different if they free range on bugs and plants. To compare apples to apples get a store bought chicken and cook it at the same time the same way and see for yourself.

 

I would have to say that if they are sex links they are all girls. The girls can be all black or have the red/gold/brown markings. The white tips will go away with age. A lot of black birds have white tips when they first feather in.

I have butchered both ee and black sex links. The sex links get bigger or at least mine did. I waited until around 24 wks for the ee and they were around 4 lbs the sex links I did at 20wks and were 4-5 lbs. I did do them at different times of year though. The ee was this spring and the sex links were last fall. I don't know if that makes a difference. Also my ee were free range and the sex links were penned up.

 

I go by how much I think I want to eat. I like to smoke or BBQ small birds around 10-12 weeks. But if you want to fry then let them grow to 3-4 lbs

 

I just butchered 5 cockerals. One light sussex and 4 americauna/bcmarans. They were hatched Jan 7th. making them approx. 5 months.
I wanted to wait longer they felt light and boney. I was very pleasantly surprised. They (of course ) had a different body shape,size and meat to bone
ratio than the meaties but dressed out about 4-5 lbs each. Perfectly respectable! I would be proud to serve these to anyone! Yes they cost more to produce.
They ate alot. Thats why I butchered them earlier than I originally planned.
Tamera