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Factory farming: Impact on animals, workers, environment, & more

Prior to the industrialization of agriculture, farmed animals typically roamed outdoors on small, independent, family-owned farms that produced a variety of foods. But recent decades have seen unparalleled changes in how animals are reared. A drive for increased productivity and profitability has caused countless small farms to be pushed out of business by the factory farms that now dominate animal agriculture in the U.S. and many other countries around the world.

What is factory farming?

Factory farming is a recent method of meat, dairy, and egg production that involves raising huge numbers—typically thousands or tens of thousands—of genetically uniform animals in a relatively small amount of space. A factory farm, sometimes called a Concentrated Animal Feeding Operation (CAFO), aims to churn out as much of a particular animal product as possible at minimal expense to the company that controls the facility. This results in meat, dairy, and eggs with prices that do not reflect their actual costs to farmed animals, workers, local communities, public health, and the environment.

History of factory farming

While raising animals for food is a long-established practice, factory farms are a recent invention. It wasn’t until the mid-twentieth century that high crop yields and technological advances made it possible for farmers to confine huge numbers of animals in high densities indoors.

What’s wrong with factory farming?

The harm that factory farming causes to animals, people, and the planet far outweighs its purported benefits.

Poor animal welfare

In today’s industrial production systems, the welfare of chickens, pigs, cows, and other farmed animals is largely ignored. These intelligent, sensitive animals are denied socialization, exercise, access to the outdoors, and the freedom to carry out their natural behaviors.

The growing public concern for animal welfare has led many consumers to look for animal products with animal welfare certifications that purport to ensure good treatment. Consumers rightly expect animal welfare labels—with names like “Certified Humane” and “Animal Welfare Certified”—to reflect best practices for animal welfare, but Farm Forward’s report, “The Dirt on Humanewashing,” reveals that this simply isn’t the case. A lack of clarity around what different welfare certifications actually mean allows factory-farmed products to be marketed and sold to conscientious consumers under the guise of higher welfare choices.

Intensive confinement

Intensive confinement is perhaps the most widely known animal welfare issue associated with factory farming. Although recent years have seen progress, the majority (66 percent, based on an estimate by industry analysts) of layer hens in the U.S. are still housed in battery cages. Similarly, keeping breeding sows in gestation crates during pregnancy remains a standard practice in the pork industry despite being incredibly cruel. Even factory-farmed animals who are not trapped inside cages, crates, or stalls are tightly packed together in sheds by the thousands or tens of thousands.

Genetic manipulation

Farmed animals are selectively bred to produce unnaturally high yields of meat, milk, or eggs at the expense of their health and welfare. The most extreme consequences of genetic manipulation can be seen in hybrid poultry, who suffer from severely compromised health as a result of being bred for genetic mutations such as rapid growth and obesity.

Mutilations (disbudding, dehorning, tail docking, and beak trimming/conditioning)

In intensive confinement systems, cows’ horns become dangerous, piglets chew each other’s tails off, and hens peck at one another’s feathers. Rather than providing the animals with an environment that meets their needs (which would be expensive), the factory farming industry’s answer to these problems is to mutilate animals’ body parts in an attempt to make the animals better suited to the conditions they live in. Common mutilations include disbudding (destroying a young animal’s horn buds), dehorning (removing horns that have already started to grow), tail docking (amputating an animal’s tail), and beak trimming or conditioning (slicing off one quarter to one third of a bird’s beak).

Culling of male chicks

Since cockerels (male chickens) cannot lay eggs and are therefore not worth any money to egg producers, male chicks born into the egg industry are routinely killed after hatching. This usually involves newborn chicks being gassed or, in a practice called maceration, ground up alive.

Labor issues and workers’ rights violations

Animals are not the only ones who suffer for the sake of cheap animal products. Labor issues and workers’ rights violations are rife within the industry. Factory farm and slaughterhouse workers, many of whom are immigrants and risk retaliation if they speak out, typically work long, grueling shifts in hazardous conditions for low pay. In a survey of immigrant dairy farm workers in New York State, almost half of respondents reported having faced workplace bullying or discrimination, and two-thirds  said that they had been injured while working.1 

Slaughterhouse jobs are some of the most dangerous in the United States. US meat plant workers are three times more likely to suffer serious injury than the average American worker. According to the Bureau of Investigative Journalism, every week US meatpackers suffer amputations, fractured fingers, second-degree burns and head trauma. Records compiled by the Occupational Safety and Health Administration (OSHA) show that each month US meat plants report at least 17 “severe” incidents involving “hospitalizations, amputations or loss of an eye.”2

Environmental impacts

Factory farming has a wide range of environmental impacts . Intensive meat and dairy production is a significant source of greenhouse gas emissions, consumes large quantities of freshwater, drives biodiversity loss, uses vast stretches of land, and pollutes our air, water, and soil.

Human health risks

Factory farming is a threat to the health of farmworkers, consumers, and virtually everyone else on the planet. Housing thousands of genetically uniform, chronically sick animals in close proximity makes it alarmingly easy for viruses like avian influenza to emerge, spread, and jump from farmed animals to humans. Industrial poultry farms could be the source of a global pandemic even more dangerous than COVID-19.

Animals in factory farms are routinely given antimicrobial drugs (such as antibiotics) to keep them alive and to make them grow faster. This overuse of drugs, many of which are medically important for use in humans, is contributing to the rise of antimicrobial resistance, which the World Health Organization has declared is one of the 10 biggest threats to global human health.

Impacts on rural communities

Factory farming impacts rural communities in a variety of ways. The air pollution and overwhelming stench of animal manure from CAFO facilities can harm the health of local residents and prevent them from spending time outdoors, reducing their quality of life. The replacement of small farms with large-scale operations is also linked to job losses and a decrease in property values.

How are factory-farmed animals killed?

In slaughterhouses, factory-farmed animals are killed and cut up on high-speed disassembly lines, compromising both animal welfare and worker safety. The method of slaughter used varies between species.

Chickens—who are slaughtered in higher numbers than any other land animal—are commonly killed using a method known as live-shackle slaughter. First, they are restrained upside down on a metal conveyor that takes them through a bath of electrically charged water to stun them. Then they have their throats slit, often by a mechanical blade, before their bodies are plunged into a tank of scalding water to remove the feathers. It’s sadly not uncommon for errors to occur during this process, resulting in birds having their throats slit while still conscious or being boiled alive.

How does factory farming affect the environment?

Factory farming makes it possible to mass produce meat and dairy, both of which have a disproportionate impact on the environment in comparison to most plant-based foods. Animal agriculture is a leading contributor to many of the biggest environmental issues in the world today.

Greenhouse gas emissions

Researchers estimate that global food production is responsible for around 35 percent of all human-caused greenhouse gas emissions. Of these emissions, 57 percent can be attributed to animal agriculture, while only 29 percent are linked to the production of plant-based foods.3

Air pollution

Each year in the U.S, fine particle air pollution caused by animal agriculture is responsible for the premature deaths of 12,700 people.4 Some of this air pollution is dust kicked up by intensively farmed animals or is emitted when fields are tilled for growing crops, some of which are fed to animals. A bigger culprit, though, is the massive manure lagoons where animal feces and urine are stored. As this waste decomposes, it emits large quantities of ammonia, a potent gas that reacts with other pollutants to form dangerous particles that can find their way into people’s lungs and bloodstream. Animal manure also pollutes the air when it is sprayed onto fields.

Water pollution

Factory farming is a major cause of water pollution. Animal manure is high in the plant nutrients nitrogen and phosphorus, which can cause the growth of algal blooms and have severely detrimental effects on aquatic ecosystems. Manure can also be full of antibiotics, hormones, harmful bacteria, and heavy metals. These pollutants can enter waterways when manure slurries are overapplied to fields or when manure storage lagoons leak or overflow.

Land usage

Keeping large numbers of animals indoors requires using vast swathes of land for growing feed crops. More than 90 million acres of land in the U.S. grow corn, most of which is fed to farmed animals.

Growing crops to feed farmed animals is generally a far less efficient use of land than growing crops directly for human consumption. For example, it takes an estimated 7.1 square meters of land to produce 100 grams of protein from poultry meat but just 2.2 square meters of land to produce the same amount of soy protein from tofu.

Who owns most farms and factories?

Although the majority of farms in the U.S. are family-owned, most meat production is controlled by a handful of massive corporations. More than 97 percent of chicken farmers in the U.S. work as contract growers for big poultry. While these farmers might technically own their farms, all the chickens they raise are owned by the company they signed a contract with, leaving the farmers with little to no control over how the birds are reared.

Factory farming facts and statistics

Solutions to factory farming

When confronted with an enormous problem like factory farming, it’s dangerously easy to fall into the trap of thinking that there’s nothing we can do, but change is possible.

Creating a higher welfare, more sustainable food system requires more than just slightly improving the factory farms that currently exist. Replacing factory farming with higher welfare forms of agriculture likely means substantially reducing the number of animals who are raised and killed for food.

The food choices that we make today as individual consumers and as institutions can help build a future in which plant-based meals are the norm and any animal products that are eaten come from farms where animals enjoy the highest possible welfare conditions.

In addition to choosing to eat different food, we need to change policies to promote alternatives to factory farming.

Farm Forward’s mission is to end factory farming.


While animal agriculture has been around for thousands of years, factory farming is new. This system of confining high densities of animals indoors is a recent invention. Food production doesn’t have to be this way. Factory farming is a mistake that can be corrected.



Carly Fox et al., “Milked: Immigrant Dairy Farmworkers in New York State” (Workers’ Center of Central New York and the Worker Justice Center of New York, 2017),


Andrew Wasley, Christopher D Cook and Natalie Jones, “Two amputations a week: the cost of working in a US meat plant,” The Guardian, July 5, 2018,


Xiaoming Xu et al., “Global Greenhouse Gas Emissions from Animal-Based Foods are Twice Those of Plant-Based Foods,” Nature Food 2 (September 2021): 724–732,


Nina G. G. Domingo et al., “Air Quality-Related Health Damages of Food,” PNAS 118, no. 20 (May 2021),


Philip H. Howard, “Corporate Concentration in Global Meat Processing: The Role of Feed and Finance Subsidies,” in Global Meat: Social and Environmental Consequences of the Expanding Meat Industry, ed. Bill Winders and Elizabeth Ransom (Cambridge, Mass.:The MIT Press, 2019), 31–53,