I have 50 ish chickens (down to 4 roosters) with only about 6 years experience... none of it includes illness and I lost my first chick to a predator recently. I still have much learning to do though, it never ends!Thanks for all of the help guys! I can see you have alot of chicken experiance how many do you have!
What do you mean when you say "chicken BREEDING sanctuary"? Any place that is still allowing the animals to reproduce is not in my opinion any type of rescue or sanctuary unless it's trying to preserve a specific species. Not knocking it as I don't know the whole story. Just saying somethings aren't as sweet as they sound on the surface. So there may be more questions you wanna ask before sending anyone that way.
Also, even if you can't do... no shame in letting extra boys feed someone else's family who will do it humanely.
Not too scare you... my last hatch had 7 out of 9 boys.... and then 1 of the only 2 girls was taken by a predator.

That being said, I did get 3 SR Silkies last year that ALL ended up being girls!

Some chick breeds can be sexed by feather length at a specific age but not past that. And I don't know which breeds, but definitely not all.