[1] https://www.ted.com/talks/dan_dennett_s_response_to_rick_war...
I don't believe this is as true as you seem to think.
Supposing someone proved to you with some future subjectivity-detecting tricorder that cows do understand all they go through, will you change your mind about the humane bullet method?
> cows do understand all they go through Also you seem to be exaggerating a bit, what do you exactly mean by all? Are you talking about their entire life or just when they're about to be slaughtered, because I think for most parts cows have a pretty happy life. The slaughtering could be done more precisely and quickly but that's really just negligence on the part of some bad actors and not something that is inherently difficult to fix.
"Cows don't understand what's happening to them, we would! Unless we wouldn't, as aliens might already be secretly controlling us and that's why we don't understand 'the meaning of life' etc. in which case it's not that bad is it?"