Will animals in trailers die after certain time even in ungenerated chunks?

So I'm current in a CDDA run and want a quiet farm at some point, I came across a trailer and found two alive male turkeys amongst 4 dead ones. The last time I played I found multiple alive ones near the farms all in trailers, but time I came across them way earlier. So I wonder if I could find them in ungenerated chunks or does it all load in at once and the time is just ticking?

nvm I just died in my run

Still I'd like to know if someone found life animals even months after they started.