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February 16, 2023

11 mins read

Farmed pigs: What are pigs used for and why is it a problem?

In the children’s story Charlotte’s Web, the main character is a pig named Wilbur who enjoys a large pen surrounded by his animal friends on a quaint farm outside a small town in Maine. When we picture pigs on a farm, many of us likely imagine an idyllic scene similar to those fed to us when we were young. Yet this image of how pigs are housed and raised on farms couldn’t be further from the truth today.

Although pigs are recognized as one of the most intelligent species, most pigs are housed by the thousands in crowded conditions with very little to stimulate them mentally. Mother pigs are often locked in crates that prevent them from caring for their young in line with their natural inclinations, forcing them to act as little more than a milk-producing machine until the piglets are old enough to be removed.

What are pigs used for on a farm?

Despite their emotional and intellectual intelligence, pigs on farms have been bred for a single purpose: to serve people and, most commonly, to be served to people as a side of bacon or ham.

Pigs for meat

The primary reason that pigs are raised on farms is to be slaughtered and have their bodies processed into meat. In 2020, over 1.5 billion pigs were slaughtered around the world. This number has been consistently trending upwards as populations around the world grow in size and wealth.1 Most pigs raised for their meat spend their lives within the confines of an indoor intensive agriculture system in a series of large warehouses. The pigs living in these systems often become inactive and unresponsive, as a result of a lack of mental stimulation.

Pigs for breeding

Pigs that are used for breeding on factory farms often find themselves locked in small cages called gestation crates. These crates are so small that mother pigs are unable to turn around and must spend their lives facing in the same direction. They are also prone to developing sores and abscesses. These conditions lead to frustration, with pigs biting at the doors of their cages looking for a release from their suffering.

Are pigs easy to farm?

Farming pigs is not easy and can take a huge toll on the physical and mental health of those that work with them directly. Exposure to particulate matter, ammonia, and hydrogen sulfide can cause respiratory issues, with an elevated risk of disease from bacterial infections, and a near-constant risk of injury, whether from machinery, waste lagoons, or the maltreated pigs themselves.

This physical danger is one reason why farming animals correlates with worse mental health than farming crops. Pigs are also highly intelligent creatures with unique personalities and the ability to empathize with one another. People who have to work in close proximity to their suffering, notably in slaughterhouses, also frequently experience poor mental health.

What do pigs eat on a farm?

The food given to pigs on factory farms is made up primarily of a combination of soy and corn. Corn accounts for about 62 percent of the average pig’s diet on a factory farm in the United States while soy makes up over 13 percent of their diet.2 A common additive in pig feed is fish meal which provides protein to young pigs. Researchers suggest that 90 percent of the fish ground into meal are fit for human consumption. Because it is more profitable to sell these fish to be turned into meal, the communities that once depended upon them as a staple, as is the case in Peru, have less access to them.3

In an alarming turn of events following the 2013 porcine epidemic diarrhea virus outbreak that killed about one-tenth of pigs being raised for pork, the deceased bodies of piglets and the feces of infected pigs were fed to pigs as a means of combating the virus and preventing its return.

Why is pig farming a problem?

A number of issues are associated with farming pigs including environmental, public health, and welfare concerns involving both the animals and surrounding communities.

Environmental and health impacts

Industrial-scale pig farming causes water and air pollution, and like all intensive animal farming it contributes to climate change thanks to direct emissions from waste and its inefficient use of land, water, and other resources when compared with arable farming.

The expansion and continued operation of industrial pig farms contributes to the degradation of natural resources and habitats in some of the most biologically diverse places on earth, including in the Yucatán Peninsula. Here the expansion of pig farming is driving biodiversity loss. The area is home to over 250 registered pig farms, Mexico’s largest carbon sink, and its most important reserve of groundwater. The pig farms in the area are causing pollution and degradation of valuable natural resources. The people in the Yucatán and throughout Mexico depend upon the health and well-being of the natural resources within the peninsula to continue to thrive.

Genetic manipulation

Genetically manipulating the animals we raise for food is nothing new. Chickens raised for meat have been engineered to grow at astonishing speeds, laying hens have been bred to produce an overwhelming number of eggs, cows have been manipulated to make vast quantities of milk, and pigs too have been genetically modified to maximize their profitability. Often the genetic modifications taking place, whether through breeding or gene-editing, are solving problems that exist due to poor animal welfare. For example, efforts to create “super muscly” pigs would not be as necessary were pigs provided with better enrichment and nutrition.

Animal cruelty

Perhaps the most glaring reason that pig farming is problematic is that the industry causes vast animal suffering. This suffering includes mother pigs being confined in crates, unable to care for their young, and lives spent in barren concrete pens. The lack of mental stimulation leads to boredom and destructive behaviors such as tail biting.4

Geopolitical issues

The corporations behind factory farms are massive and have no qualms about getting involved in politics to benefit themselves. Through their efforts, numerous initiatives seeking to improve the welfare of pigs on factory farms have been challenged and shot down. The ongoing debate concerning California’s Prop 12 is just one example.


The use of drugs in pigs is detrimental to public health for several reasons.

Growth promoters

The primary growth promoter given to pigs is ractopamine. This drug causes pigs to develop more muscle than they otherwise would, given their diet and lack of exercise. Though research on human impacts is slim, some suggests that in humans the drug can cause an increased heart rate. There are also reports of people being poisoned following their consumption of pork from pigs fed the substance.5


Tetracycline is one of the most widely used antibiotics in pigs around the world. Analyses have shown that genes resistant to the drug are some of the most abundant antibiotic-resistant genes in bacteria found in pigs.


Pigs host parasites that are capable of being passed on to people. One example of this is ascariasis, a parasite that causes difficulty breathing and weight loss in infected individuals. The parasite can be contracted by eating vegetables and fruits that have been fertilized with pig manure or by not washing one’s hands thoroughly following handling pigs.


Because pigs carry some parasites and diseases that can be easily transmitted to other pigs or even people, hygiene is of the utmost importance to facilities raising thousands of pigs. In an effort to increase hygiene, these facilities often choose to reduce animal welfare by keeping pigs in barren concrete pens instead of offering bedding such as straw that would provide the opportunity for pigs to engage in natural behaviors like rooting and nesting.6

Labor issues

The issues faced by the employees and staff of pig farms are numerous. Farmworkers tend to be responsible for carrying out procedures such as clipping teeth, neutering, and docking the tails of screaming piglets. Working on a pig farm leads to workers being exposed to large amounts of noise and ammonia from the thousands of pigs being housed in the sheds, both of which can cause long-term health problems.

Pig intelligence

Pigs are recognized as one of the most intelligent species. They are skilled at simple video games, and form tight-knit groups with complex social relationships. When not being factory farmed, they take pride in their surroundings and maintain a clean environment. Some pigs have even been documented decorating their enclosures.7 This is in direct contradiction to the widely held belief that pigs are dirty and unintelligent creatures.

Is it profitable to farm pigs?

The question of whether pig farming is profitable is irrelevant given the detrimental impacts of pig farming on the environment, public health, and worker and animal welfare. The only reason that pig farming is profitable as we know it is because it is propped up by subsidies funded by taxpayers, by a lack of effective oversight to ensure workers’ rights are respected, and by the crowding and suffering of millions of pigs.

How much does a pig cost?

The relatively low cost of buying the products produced from farmed pigs is due to the many corners the industry is allowed to cut. To stay inexpensive, the industry depends upon government subsidies, poor working conditions, and horrendous animal welfare.


Raising pigs for food causes harm to the environment, public health, and animal welfare. Yet many new and innovative replacement products are being brought to the market every year that provide the taste of our favorite animal-derived foods without requiring that the animals die for our enjoyment. There has never been a better time to cut back on, or eliminate, pig products in our diets.



Yukiko Nozaki, “The Future of Global Meat Demand—Implications for the Grain Market” (Mitsui and Co. Global Strategic Studies Unit, September 2016),


Decision Innovation Solutions, “2016 U.S. Animal Food Consumption Report” (Institute for Feed Education and Research, December 2017),


Clare Leschin-Hoar, “90 Percent of Fish We Use for Fishmeal Could Be Used to Feed Humans Instead, February 2017),



World Animal Protection, “A Pig’s Tale: Exposing the Facts of Factory Farming” (World Animal Protection, 2018),


“Food Safety Fact Sheet: Ractopamine Fact Sheet,” Center for Food Safety, February 2013,


Torun Wallgren, Nils Lundeheim, and Stefan Gunnarsson, “Impact of Amount of Straw on Pig and Pen Hygiene in Partly Slatted Flooring Systems,” BMC Veterinary Research 16 (October 2020),


Joseph Ruddleston, “Rescue Pig Picks Out Flowers To Decorate Her House,” The Dodo, August 11, 2022,