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Pig Farming: Why Is It Bad, and Do Pigs Suffer?

November 23, 2021

Every year millions of pigs suffer on factory farms that show little or no regard for their welfare. They are locked in crowded cages that prevent natural behaviors or even a full range of motion. In addition to the suffering they cause, these farms are responsible for a large amount of pollution that both disrupts local communities and affects the wider environment we all share.

About Pig Farming

What Is Pig Farming Called? 

Pig farming is referred to as either pig or hog farming. Within the industry there are a number of different names for pigs based on each animal’s purpose on the farm. A sow is a female pig who has given birth to a litter of piglets, or baby pigs, while a gilt is a female pig that has not. A porker is a pig that is being raised for pork. They are typically slaughtered at between four and six months and reach about 132 pounds. A baconer is a pig that is being raised for bacon. They live between eight and ten months and reach between 175 and 200 pounds before slaughter. Male pigs can be hogs, castrated pigs, or boars, intact males older than six months. 

How Profitable Is Pig Farming? 

Like the majority of animal agriculture, hog farming is not highly profitable. In 2017, the most recent U.S. Census of Agriculture totaled pig sales at just over $26 billion. This means that before expenses, the 67,000 farms that raised pigs each made $404,908. Market analysis from the same year highlighted the vulnerability of the industry to changing demand and feed prices. The animal agriculture industry was especially hard hit by the COVID pandemic in 2020 when millions of pigs were killed without being sent to market due to shuttered slaughterhouses not being able to process their carcasses. 

Pig Farming Requirements

Unfortunately, there are very few regulatory requirements for pig farming in the United States. Most of the guidelines followed by pig farmers originate from the industry itself, or programs that allow farmers to opt in so that they can use recognized branding such as “Certified Humane Raised and Handled” on their labels to increase sales. 

Pig Farming Facts and Statistics

Why Is Pig Farming Bad?

There are a number of problems with pig farming, ranging from the welfare impacts of accepted standard practice within the industry to its effects on the environment. 

Artificial Insemination

Artificial insemination is the predominant method by which sows and gilts are bred on industrial farms. It consists of a farmer inserting sperm that has been collected from a boar into a sow or gilt that is experiencing estrus. The method allows for greater genetic diversity when breeding and allows the ejaculate from one boar to be spread across several different sows, providing a more cost-effective method of breeding. 

The Boar

To stimulate a boar to ejaculate without actually breeding with a female pig, farmers often use a dummy. The boar will be trained to mount the dummy and thrust while a farmer uses their hands to stimulate the boar until ejaculation occurs. 

The Sow and/or Gilt

The female pig is typically inseminated by a farm staff member several times to ensure she is successfully impregnated. Female pigs will go into heat and be bred as little as three days after a litter of piglets has been removed from them. This often results in a female pig being forcibly impregnated multiple times a year. 

Gestation crates

Female pigs are frequently placed into gestation crates, or farrowing crates, shortly before they are due to give birth. Once locked into the crate the mother pig is unable to turn around and is only able to walk a few steps. The purpose of the crate is to prevent the mother pig from rolling or sitting on top of her young and crushing them under her weight. The risk of crushing is increased by the selective breeding of pigs for large litter and body size. Because litters of pigs are larger, the piglets are often smaller and weaker at birth thus more likely to be crushed. The problem is multiplied by the size of the mother sow, which is often 200 pounds or more with the purpose of increasing profit at slaughter. 

Castration and Tail Docking

Piglets undergo castration and tail docking at only a few days old and often without sedation. The procedure is often carried out by farm staff rather than veterinary professionals. 


Male piglets are castrated to reduce aggression toward other pigs and also reduce “boar taint” in their meat—a flavor that many consumers dislike compared to the meat of castrated males. There are two methods of castration in the United States. The first is surgical castration, which consists of restraining the piglet and cutting the testes out of the scrotum. Anesthesia is not typically used for this procedure. The procedure results in high levels of pain for the piglets who squeal and tremble. The alternative method of castration is immunocastration that must be performed under the guidance of a veterinarian and is thus less common. This method consists of two injections several weeks prior to slaughter to temporarily castrate the pigs and thus eliminate boar taint in the meat. 

Tail Docking

The swine industry in the United States considers tail docking standard practice in order to prevent tail biting. While the causes of tail biting are not well understood they are likely related to overcrowding, and a lack of adequate ventilation, overall health, and nutrition. The consequences of tail biting can be serious and include bleeding, wounding, and even paralysis. Alternative, less invasive, forms of managing tail biting include providing adequate nutrition for pigs to prevent them from feeling the need to chew on each other’s tails. Guidelines for pig welfare in Australia dictate that tail docking should be avoided as much as possible and instead alternative methods of management such as environmental manipulation should be evaluated for effectiveness first. 

Slaughter at an Enormous Scale

Per the United States Department of Agriculture Economic Research Service, from January to September 2020 over 97 million pigs were slaughtered in the United States. This number was slightly lower for the same period in 2021, with 95,697,900 pigs slaughtered. 

Trapped in a Barren Environment

Pigs are recognized as some of the most intelligent beings alive. Despite this, their housing on farms is often barren. Straw is one of the most effective types of environmental enrichment for pigs as it provides them with the opportunity to root and create nests. Despite this, straw is widely underused on farms in order to make sanitation easier and avoid the risk of blockage to the manure drainage system. Instead, pigs are commonly given chains or plastic or rubber toys which they often quickly lose interest in. 

Treated with Brutality 

Workers on pig farms have come forward and spoken out about the treatment and conditions endured by the pigs they worked alongside. One worker in Illinois wrote a three-page letter in 2015 detailing the suffering she witnessed including pregnant pigs being kicked and beaten with steel bars. 

What Do Pigs Eat on a Farm? 

Pig feed changes from farm to farm but is typically made up of corn or soy and additives. Additives can include antibacterial agents, antiparasitics, metabolic modifiers, acidifiers, probiotics/prebiotics, botanicals, flavors, and enzymes. In many states pig farmers can give human trash to their animals. 

Do Pigs Suffer When Slaughtered? 

It should not come as a surprise that pigs suffer at the time of slaughter. In addition to being surrounded by dozens of other fearful pigs during transport and entry to the slaughterhouse, the process of slaughter is filled with welfare issues. The process starts when the pigs arrive at the facility and are escorted to the area of the slaughterhouse meant for stunning. Here the pigs are stunned in an effort to prevent further suffering. This stunning can take several forms including the use of a bolt gun that causes blunt force trauma to the skull or atmospheric stunning that involves introducing CO2 into the atmosphere at high enough levels to suffocate the pigs. Unfortunately, stunning is frequently not performed correctly due to a lack of training or time on the part of the slaughterhouse workers. This can easily lead to many pigs still being able to experience pain as they are killed. 

Is Pork Bad for the Environment? 

A large pig farm can create upwards of 1.6 million tons of manure in one year. These massive quantities can be hard to manage, and manure can make its way into the air and nearby groundwater, degrading the local environment for surrounding communities and even causing health problems. This manure is also rich in phosphorus and nitrogen, and when these nutrients ultimately reach the ocean they can increase the severity of algal blooms, having lasting effects on marine ecosystems and killing large numbers of fish. 


Intensive pig farming compromises the welfare of millions of animals every year and causes them to suffer unduly. Thankfully we can make a difference by making conscientious food choices. Choosing to exclude foods made from the flesh of pigs means decreased demand, which in turn can bring down the number of animals suffering on large-scale pig farms. The increased availability of alternative proteins and plant-based meats means that making such decisions has never been easier.