I have read they keep it partially frozen so it won't spoil.
I raised my own chickens for several years, dressed them out. Either froze whole or cut up, best chicken you ever ate. We used to raise them when I was growing up and I learned to kill and dress them. I had
to laugh at hubby, even he was kind of squeamish when I killed them.
Mom would pull off their necks, but I read a more humane way. Tie the legs together, slit the arteries on
each side of their neck, they just kind of go to sleep as the blood drains out.
Sounds gross but that's what they are for.