Explains the pointlessness of insignificant objects when compared to more pertaining aspects.
In another usage, it goes to dismiss collateral damage.
Literally: When a cow dies, it dies.. nobody gives a fuck.
A: The flood killed 4 people..
: Thats nothing.. What about the millions of livestock lost? No one considers their suffering..
A: Dude, when human deaths are involved, cow die, cow die.
Mom: If you keep playing video games all day, who's gonna do your homework?
Son: Cow die, Cow die..