What Is Factory Farming and Why Is it Bad?

The vast majority of farmed animals are raised on crowded factory farms that cause climate emissions and environmental pollution.

factory farm cow

Explainer Food Industry

Factory farming is a method of raising livestock animals that maximizes efficiency in industrial operations that dictate feed, space, growth and timing of slaughter. The vast majority of farmed animals are raised under this system, which continues to grow and be applied in more and more countries worldwide. Yet factory farming is also responsible for animal cruelty, public health risks and massive environmental impacts. The factory farming industry cannot continue its current rates of expansion and production without severe damage to the planet and global food system.

What Is Factory Farming?

Factory farming is an intensive and often largely automated system of raising animals for human consumption. In factory farms — most of which are concentrated animal feeding operations or CAFOs — animals of one species live crowded together in extremely small spaces, often with little or no access to the sun or fresh air. Many of their vital processes — such as being born, fed, watered and inseminated — are highly mechanized, with little regard for their physical well-being and social and psychological needs.

When Did Factory Farming Start?

The origins of factory farming can be traced to the mechanization of pig slaughterhouses in the U.S. in the 1930s. From there it expanded quickly to other species and other countries, including the U.S. poultry industry. In the U.K., factory farming began with the Agriculture Act of 1947, which subsidized the CAFO industry. By the late 20th century it was introduced throughout the Global North, and it continues its expansion in Latin America, Asia and Africa to this day.  

Where Is Factory Farming Most Common?

Factory farming has spread around the world, but it’s most common in developed countries like the U.S., the U.K., Australia, Canada and the European Union. Around 99 percent of farmed animals in the U.S. are raised on CAFOs. They are concentrated in states like Iowa, Illinois, Kansas, Nebraska and North Carolina, often densely concentrated in regions with water and air pollution. In some counties, the number of farmed animals exceeds the human population. In the U.K., around 73 percent of farmed animals are kept in factory farms. These are concentrated in North and East Yorkshire, Lincolnshire, Norfolk, Suffolk, Shropshire, Herefordshire, Gloucestershire and Somerset in England, and the counties of Tyrone and Antrim in Ireland.

How Does Factory Farming Work?

Factory farming encloses large numbers of animals who have been selectively bred for greater productivity, often in cages or pens, and aims to produce the largest quantity of meat, milk, and eggs as possible in the shortest time period.


There are around 33 billion chickens in the world on any given day, and most of them live in factory farms. In the U.S. alone, there are around 518.3 million chickens, 99.9 percent of them in CAFOs. 

Both broiler chickens and layer hens live in poor conditions that compromise their welfare. Most of them can’t spread their wings or run around. A majority of broiler chickens — those raised for their meat — are slaughtered when they are only 6 to 7 weeks old, while layer hens are usually sent to be gassed when they are no longer useful to the egg industry. More than 6 billion male chicks born to layer hens are killed globally every year, because chickens are bred for their functions and only the female layers serve a purpose in the industry.   


There are more than 450 million farmed turkeys in the world at one time. Most of them are concentrated in Brazil, Germany, France, Italy and particularly the U.S., where about 214 million turkeys are killed each year. 

On factory farms, turkeys live in highly controlled indoor systems and are encouraged to eat more and move less. They grow astonishingly quickly, and are killed at between 5 and 6 months old. 


The global population of farmed cows is around 1 billion. In the U.S. alone, there are almost 99 million cattle and calves, according to the latest USDA report. Most dairy cows live in factory farms, crowded into small spaces and kept in poor conditions. 

There is no such thing as a “retired” dairy cow, they are killed at about 6 years old when they can no longer produce milk, most of them ending up as beef. Those who are raised exclusively for their meat are killed when they reach between 2 and 3 years old. Calves raised for veal are killed at around 16 to 18 weeks of age.


There are over 780 million farmed pigs worldwide. Most of them are raised in China, where there are almost 450 million. The European Union and the U.S. are the second and third largest producers, respectively. 

In 2019, 129 million pigs were killed for food in the U.S. More than 98 percent of them were raised on factory farms, where their lives are bleak. Typically, these pigs are killed when they are 5 to 6 months of age, while reproductive sows are sent to slaughter when they are too exhausted to keep giving birth, aged about 18 months to 2 years.


Fish and other aquatic animals are raised in numbers so high that they are often measured in tons. It’s calculated that over 82 million tons of animals were produced globally from aquaculture in 2019. Aquaculture production surpassed wild catch in 2015.

In terms of individual numbers, it’s estimated that between 51 billion and 167 billion farmed fish were killed for food globally in 2017. These animals are raised in unhealthy, unclean, crowded, unacceptable conditions and suffer constant stress and anxiety. 

What Are The Types of Factory Farming?

Factory farms come in many shapes and sizes, but they all have in common the crowded and poor conditions animals face while waiting for their imminent slaughter. Fish, chicken, cows and pigs are the most common and widely farmed species. Other animals raised on factory farms include turkeys, sheep, goats, frogs, rabbits, mink, foxes and more animals raised for their meat, milk and eggs as well as for their skin and fur.

Is Factory Farming Cruel?

In factory farms cruelty and slaughter is standard practice

Inhumane Treatment

Confined and deprived of their basic social, physical and psychological requirements, without any possibility of autonomy, animals are definitely not treated as sentient beings in these intensive systems, but rather as objects.

Chickens Are Debeaked

As a consequence of overcrowding, chickens living in CAFOs tend to peck at themselves and each other. To reduce injuries — and thereby avoid economic losses  in countries where it’s legal to do it, the industry removes part of the chickens’ beaks by cutting or burning them. Beaks are very tactile and sensitive, and function like hands do for humans. After debeaking, chickens show pronounced changes in general activity and attitude, showing signs of pain and depression

Cows and Pigs Are Tail Docked

To once avoid injuries to human workers caused by overcrowding, cows are often dehorned, pigs are often tooth clipped, and both are usually tail docked. Like debeaking, these procedures are mostly executed without anesthesia

Animals Are Confined

Most animals confined in factory farms are deprived of quality air and light. Their movements are limited, causing them physical atrophy. They are permanently surrounded by their own feces and waste, and even sometimes by their fellows’ corpses. They are also cruelly separated from their families and friends, with associated psychological repercussions.  

Genetic Breeding

The animal-related industries have developed breeds suited to their needs, like hens that lay more than 300 eggs per year, cows that produce an unnaturally high quantity of milk or foxes that produce more fur than they should. The result are farmed animals that are unable to stand up or walk, with heart diseases and chronic physical pain, among other issues.

Forced Molting

Plumage molting is a natural seasonal process among birds. Egg production is paused during this phase, but it’s boosted once the molting ends. The egg industry starves the hens and manipulates the lighting of their enclosures to induce molting in birds that are losing productivity, in order to increase the quality and quantity of eggs they lay. Forced molting not only causes stress and discomfort to hens, but can also harm their skeletal system.

Unhealthy Levels of Ammonia

Ammonia is a gas derived from animal waste. Constant exposure to ammonia can be harmful not only for nonhuman animals but for humans as well, causing eye, nasal, skin and lung damage for slaughterhouse workers. Also, ammonia and other particulate matter originating from animal agriculture are linked to higher incidences of cancer, cardiovascular disease and stroke. Nevertheless, these gas emissions are lightly regulated.

Why Is Factory Farming Bad?

Factory farming is responsible for the deaths of billions of animals every year. It also contributes around 14 percent of global greenhouse gas emissions, primarily methane from cattle farming and land use change, as well as air and water pollution. 

Animal Welfare

Animal exploitation in factory farms is among the main causes of suffering inflicted by humans on other animals, known as “anthropogenic suffering.” Although various laws establish minimum animal welfare conditions, their real purpose is often just to keep animals alive and healthy enough to slaughter for food and profit. Meanwhile, billions of animals remain subject to confinement, in pain, with health problems and unable to establish healthy social relationships.

Environmental Impact

Factory farming damages the environment in several ways. It’s linked to water and air pollution, as well as land degradation. It also relies on excessive use of valuable resources such as land, water, crops and energy. It’s among the primary causes of rainforest deforestation and is a major driver of global warming because of its high greenhouse gas emissions, to name just a few of its negative ecological impacts. 

Human Health Issues

Whether you consume animal-origin products or not, you can be affected by the negative impacts of factory farming on human health. 

Because animals are crowded and stressed, CAFOs are the perfect place for viruses to mutate, spread and grow stronger, making factory farming a generator of zoonotic diseases. For the same reason, the industry uses a lot of antibiotics in attempting to prevent illness and infections, increasing the risk of antibiotic resistance in diseases that affect both animals and humans. So not only is factory farming very likely to be the cause of the next pandemic, it could be reducing the effectiveness of antibiotics with serious long-term consequences for modern medicine. 

Rural Communities

Of course, negative effects of factory farming fall most heavily on workers and the rural communities that live near their units. In addition to being directly exposed to different pollutants, pesticides and antibiotics, with a high probability of effects on their health, these people have to put up with strong odors that diminish their quality of life on a daily basis. On the other hand, small producers are increasingly overwhelmed by the monopolistic growth of large factory farms and the companies that run them, being forced to work for them or go bankrupt.

How Are Animals Killed on Factory Farms?

Slaughtering methods vary by species and country. Many chickens are gassed to death or dunked into electrified water. Cows, goats and sheep are often shot in the head with a retractable bullet to be knocked out before they are killed, and pigs are stunned with an electrical gun. In many places around the world with poor regulations about killing methods, animals’ throats are slit while they are still alive. 

In any case, animal welfare laws don’t ensure painlessness for animals. All too often, maximizing production and profit outweigh concerns about animal suffering. Mass culling of piglets and the chicks being buried alive in response to COVID-19, as well as the inhumane methods recently applied to kill birds exposed to avian flu are proof of that. 

Why Isn’t Factory Farming Illegal?

Because of all the previous arguments, many people are in favor of ending factory farms and there also seems to be a political appetite for it. Yet intensive farming is still technically legal almost everywhere. The reason is that laws are designed to protect the food industry’s largest corporations, including those related to animal agriculture. In fact, ag-gag laws are often used to cover up animal abuse on factory farms and silence scientists and animal rights activists who try to expose it. 

What Are Alternatives to Factory Farming?

Although farming crops is the simplest alternative to animal factory farming, there are also other choices such as growing fungi and algae. Also, in recent years the lab-grown meat, dairy and materials industry has been growing fast and seems to be close to bringing a range of products to market.

Factory Farming Facts and Statistics

What You Can Do

You can help slow climate change, reduce animal suffering and contribute to public health and social justice by reducing — or, even better, eliminating — your consumption of animal-based products. By eating mostly plants, fungi and algae and supporting public investment in lab-grown meat and dairy, you can help support a transition away from factory farming and join the community of people working in favor of the animals, the planet and positive social change.  

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