This shocking undercover video of cow slaughter was captured in Mexico by Tras Los Muros in their documentary Matadero. Although filmed in Mexico, modern slaughterhouses work similarly in all countries.

This video shows the huge gap between the image of "a clean and fast kill" that the general public has over cow slaughter, and what cow slaughter is actually like.

It's important to take into consideration that the animals start experiencing terror as soon as they are violently loaded to transportation trucks. Since many farms are in remote locations, the transportation period is often very long and grueling. So grueling that some animals don't survive it.

Once the cows arrive at the slaughterhouse, they are usually kept in holding areas, where they can easily smell the blood and sometimes even hear the screams of cows who are slaughtered. Cows may be kept for days in these holding areas, depending on the size of the slaughterhouse.

As can be seen in this video, the cow slaughter itself is just as violent and horrible for the cows.