Because of its low coast and easy use, the bolt gun is the most common tool for slaughtering animals. Photo credit Tras los Muros

An undercover investigation into the Mexican animal farming industry has revealed what many of us already know but often choose to ignore: the treatment of animals in factory farms is brutally violent and horrifying. The investigator and photographer behind the project, who keeps their identity secret for their own protection and goes by the name Tras los Muros (Behind the Walls), captured haunting footage from 58 different farms and slaughterhouse; images include pigs being clubbed to death, horses wild-eyed in the moments before death, and cows being packed like sardines onto the back of trucks to be shipped across the country. The images are nightmarish.

“I hope that with this footage, the public understands that slaughterhouses are one of the largest and most systemic forms of oppression and violence against animals,” explained Tras los Muros an email to Project Earth. “And it’s important to emphasize that, although all the material exposed here has been collected in Mexico, the objective of this investigation is not simply to show what happens in this particular country… everything I show in the photos occurs in a similar way everywhere in the world.”

The investigation, which is largest undercover investigation into Mexico’s animal farms to-date, is gaining traction in Mexico, where the images have been shared widely on social media and in digital publications.

Map showing the location of the 58 slaughterhouses featured in the investigation. Graphic credit: Tras los Muros

“The industry invests a lot of money in expensive advertising campaigns showing an idyllic image of livestock,” explained Tras los Muros. “But that does not correspond to reality at all.” Over the course of two years, the undercover photographer gained the trust of slaughterhouse workers and was able to obtain footage of cows, pigs, chickens, goats and horses in their final moments of life.


A pig slaughterhouse in Oaxaca, Mexico, where 300 pigs are slaughtered daily. Photo credit: Tras Los Muros

The investigation documented many actions that, in addition to being disturbing in nature, are also illegal under Mexican animal welfare laws. For example, there’s footage of animals being killed by clubbing, kicking, punching, and electric shock, all of which are banned. Some of the more haunting images from the investigation show animals in their last moments of life, like a horse being killed by electroshock (a quick side note for everyone disgusted by the fact that they eat horses in Mexico; while slaughtering horses for meat is illegal in the U.S., exporting horses to other countries for slaughter isn’t, and about 10,000 retired race horses are sent to Canada or Mexico to be killed for meat annually).

A horse moments before slaughter. Arriaga (Chiapas), Mexico, 2017. Photo credit: Tras los Muros


The documentary project contains an endless display of confinement and killing that, regardless of its legality, displays the brutal nature of animal slaughter. “My work is only a small contribution to all the effort that thousands of activists are making throughout the world,” said Tras los Muros. “I hope it will help add more people to fight for all the animals that are oppressed in farms, slaughterhouses and other areas of exploitation.”

It’s important to note that the nightmarish practices revealed from this investigation aren’t unique to Mexico. “The undercover footage of these farms in Mexico is horrifying, but the factory farms and slaughterhouses in the United States are equally cruel and disturbing,” said Ashley Byrne, a spokeswomen for PETA. “Standard legal practice in the U.S. includes extreme confinement, animals living in their own filth, mutilating animals with no pain killers – for instance with pigs, cutting off their teeth, their testicles or their tails with no pain killers whatsoever.”

It seems like every other day another video comes out exposing the cruel practices in American factory farms; this past November an undercover video showed how cows at a Florida dairy farm were beaten and kicked, and earlier this month a video reportedly showed workers at a chicken farm in Virginia killing sick or injured birds by running them over with forklifts or impaling them with nail-filled pipes. Just all around horrific stuff.


Considering that the average American eats more than 210 pounds of meat every year—almost triple the global average – we can’t point the finger at Mexico without acknowledging our own guilt. “Generally, life for farmed animals in the United States, who are used for meat, for milk, for eggs, is just pure misery,” said Byrne.

Chickens hanging on the processing line at a poultry plant, Chapala (Jalisco), Mexico, 2016. Photo Credit: Tras los Muros

One More Reason to Care: the Environment 

Let’s say you were able to watch the entire 39:30 seconds of horrific footage shot by Tras los Muros, and you were still fine with munching another burger, there’s still another important reason to rethink your meat consumption: the environment. Livestock or livestock feed occupies 1/3 of the earth’s entire land surface, is one of the leading drivers of both rainforest destruction and ocean dead zones, and uses about 1/3rd of the earth’s total freshwater. The livestock sector also releases about 15% of global emissions. Every step that goes into meat production–growing the grains that feed the animals, processing and transporting said grains, transporting the animals—has some impact on global warming, and it adds up to about 15% of all emissions! That’s more than the exhaust from all the world’s cars, trucks, trains, ships, and airplanes.


But it doesn’t have to be that way. One of the best ways that you can reduce your carbon footprint is by eating less meat. It’s been estimated that if Americans gave up meat and cheese just one day a week, it would be like taking 7.6 million cars off the road.

“Exposure is very important when it comes to convincing consumers to change their habits,” said Byrne, “and I think the combination of factors, including non-meat options becoming more available, animal agriculture becoming increasingly exposed as environmentally unsustainable, and of course exposure projects like this one in Mexico, will all help bring about positive change.”

Cows being transported to slaughter, Aguascalientes, Mexico, 2017. Photo credit: Tras los Muros