The key metric for ‘human’ actions is to avoid needless suffering. Livestock processed humanly is not panicked, not given a slow painful death, it should be quick, clean, and without pain.

Living conditions are human if they don’t create needless suffering, i.e. animals living in a open farm are human, animals living their lives in changes is inhumane.

I think the golden rule applies, treat others how you would like to be treated, is basically being humane.