The way that most slaughterhouses kill cows is to use a pithing cane. To use the pithing cane, there must be hole put in the cows head with the use of captive bolt stunning. Once the animal is stunned the rod is then inserted into the hole and pushed all the way into the cows brain. the rod then stays in the hole and is thrown out with the remains of the cow. In older times, they used to slit the cows throat and let them bleed out.