Skip Navigation

How do chicken farms work, and is chicken farming cruel?

Up until the mid-twentieth century, most chickens were produced on small-scale diversified farms, where chickens typically had access to the outdoors and could express natural behaviors. This historic norm has changed in recent decades, and today just a handful of corporations control every aspect of chicken farming from breeding to slaughter, prioritizing their profits over the health and well-being of the birds in their care, of their staff, and of the environment.

What are chickens farmed for?

The 40 billion chickens farmed around the world per year are bred for their ability to produce eggs or be killed for meat.

Egg-laying hens

During 2020, the U.S. housed some 325 million laying hens that produced 96.9 billion table eggs, an average of 296 eggs per year.1 The number of eggs laid by a commercial laying hen in a single year has increased significantly since 2000, when the average chicken would lay 264 eggs per year. This increase is largely attributable to genetic manipulation through breeding programs.

Meat production

Within the world of industrial animal agriculture, chickens raised for meat are called broilers. According to the U.S. Department of Agriculture, in 2020 9.22 billion chickens were raised for meat. All of these chickens combined weighed 59.4 billion pounds and, when assigned a dollar value, were worth $21.7 billion.2

What do chicken farms look like?

Though billions of chickens are raised every year, their lives are all similar due to the industrialization of egg and chicken meat production. On broiler farms, forty thousand chickens or more live crammed together in one large windowless barn, often longer than a football field. Lighting is controlled so that the birds are active at night and keep eating to put on weight faster. The waste from tens of thousands of chickens creates a strong smell of ammonia, in spite of large vents that move air through and out into the surrounding area, causing irritation to the birds’ eyes, throats, and skin. One chicken farm can have dozens of such sheds, and produce millions of birds in just one year.

Genetic manipulation

Scientists within the industry have used intensive breeding programs to increase the productivity of chickens. In laying hens, high production leads to diseases such as osteoporosis and bone fractures. The intensive breeding of chickens raised for meat has led to birds that experience disorders of the skeletal and metabolic systems, which severely compromise their health and well-being. Chickens suffer because industry professionals choose to prioritize production and profit rather than the welfare of the individual birds.

Battery cages

As of 2020, 70.7 percent or 231.7 million laying hens lived their lives in battery cage systems. Experts believe that living in battery cages is devastating to chicken welfare, because the birds are unable to express natural behaviors such as nesting and are subject to overcrowding.

Forced molting

Molting is a natural part of a chicken’s life when they reduce the amount they eat, stop producing eggs, and lose most of their feathers. Once molting has ended, hens begin laying eggs once again but their reproductive system has been rejuvenated and they lay more eggs of better quality. Forcing birds into molting as a means of raising their productivity is common practice in the egg production industry. Forced molting is accomplished by withholding food, water, or both, frequently resulting in a higher mortality rate and leading to increased stress for the birds.3

Beak trimming

Beak trimming (also known as debeaking) consists of removing one-third to one-half of the birds’ beaks and is typically performed as a means of managing cannibalism and feather pecking, behaviors caused by confinement, density, and lack of enrichment in an overcrowded flock of chickens. Because there is no industrial housing system that meets all of a chicken’s needs, beak trimming practice is performed on most chickens, whether free-range, cage-free, or in battery cages. A chicken’s beak is a sensitive organ that plays an important role in expressing a variety of natural behaviors. Following beak trimming, birds are likely to experience anatomical, physiological, and biochemical changes and display signs of both acute and chronic pain.4


It likely comes as no surprise that the day of slaughter is filled with suffering for chickens. In most slaughterhouses, birds are first hung upside down by their feet and then shackled to a conveyor line. The birds’ heads are then run through an electrified bath intended to stun them before their throats are slit. After slaughter, the birds are immersed in scalding water to loosen their feathers to prepare them for plucking. However, line speeds for slaughtering birds can be as high as 140 birds per minute. As a result of high line speeds many birds are not stunned or slaughtered properly, which means that an estimated 1 million birds are boiled alive every year because workers were not given sufficient time to ensure the chickens were slaughtered before they were submerged in boiling water.

Is chicken farming cruel?

Industrial farming methods used to raise virtually all commercial chickens causes suffering for billions of chickens every year. The handful of companies that dictate industry standards prioritize profitability over animal welfare, leading to a low quality of life before an early death .

Toxic environment

Industrialized farms house thousands of birds in a relatively small area, and as a result their conditions can become dangerous. Litter becomes soaked with urine and ammonia causing irritation to the skin. Chickens may develop footpad dermatitis that can lead to deep and painful ulcers. Excessive ammonia levels in the litter and air can lead to eye lesions,5 lung damage, skin and respiratory problems, and even blindness.6

Genetic modification

For the past forty years chicken companies have focused on genetically modifying birds for increased productivity despite the toll that intensive breeding takes on the animals’ welfare. Chickens raised for meat have been bred to grow so fast that many develop bone diseases, heart problems,7 and lameness.8 Similarly, laying hens have been bred to produce so many eggs in a year that they frequently fracture bones.9

Light manipulation

During the summer months, when days are longer, chickens naturally produce more eggs than in the winter. The industry capitalizes on this tendency and daily exposes chickens to 14 to 16 hours of light throughout the year to maximize productivity.

Cruelty to workers

The conditions faced by the workers in chicken farms and slaughterhouses can often be overlooked by both advocates and the general public. The reality for the people working in these facilities is grim. At slaughterhouses, lines operate so quickly that workers are left to cut apart an animal in mere seconds. Not only are their tasks extraordinarily dangerous, but the environment in which slaughterhouse employees work is fraught with slippery floors, loud noises, dust, and dangerous chemicals.

Impacts on rural communities

As is the case with all factory farms, industrial chicken operations are more likely to be located in communities of color and those with higher rates of poverty. These communities are then forced to endure the health and environmental consequences of housing a factory farm, which produces emissions including methane, ammonia, carbon dioxide, and nitrogen.10 Ammonia causes respiratory problems in farmers and neighbors, and volatile organic compounds cause headaches, nausea, and increased risk of cancer. Nitrogen and manure pollutes waterways and can seep into groundwater. Hydrogen sulfide emissions cause odors for downwind residents, and contribute to acid rain and haze. Greenhouse gasses such as methane contribute to climate change not just for neighboring communities but the planet.

What are the health impacts of chicken farms?


Chickens around the world are becoming more resistant to common antibiotics. This trend is especially prominent in China, India, and a number of lower-income countries such as Kenya, Uruguay, and Brazil. These nations raise about one-fifth of the chickens produced globally and some export large quantities of meat to countries around the world. By volume, though, the United States is the third-largest consumer of antibiotics for farmed animals, following China and Brazil. The application of antibiotics to animals who are not sick—to promote growth or to prevent illness—leads to the development of “superbugs,” which are resistant to antibiotics and pose a threat to human health.

Antiparasitic resistance

Antiparasitic resistance is caused by the repeated deworming of chickens that results in parasites developing resistance to the dewormers used. Recent research shows the growing global rise of resistant parasites. Factory farms create conditions ripe for the spread of parasites, conditions that almost ensure reliance on these drugs, which perpetuates the problem. The development of resistance can be slowed by the responsible use of drugs in line with FDA guidance, but cannot be stopped completely.

Avian influenza

Industrial chicken farms represent an ideal environment for the spread of avian influenza, or bird flu. The 2022 avian influenza outbreak in the United States swept 46 states and impacted millions of birds, including over 40 million poultry around the country.

E. Coli and Salmonella

Salmonella and E. Coli are two kinds of bacteria that can be found on chicken meat. If chicken is not prepared in keeping with health guidelines, the bacteria can spread to other foods or whoever consumes the meat. Both types of bacteria can cause diarrhea, fever, and cramping.

Breeding ground for pandemics

Industrial chicken farms provide the perfect environment for generating pandemics. The genetic similarity of the birds allows disease to spread quickly, and the routine subtherapeutic use of antibiotics facilitates the development of resistant superbugs. Of specific concern is bird flu, which is currently sweeping the nation’s birds. Though few humans are impacted by the virus as yet, farms where workers are routinely exposed to thousands of birds provide an ideal environment for transmission.

What are the environmental impacts of chicken farms?

Water pollution

Waterways such as rivers, lakes, and streams host biodiverse but sensitive habitats. Chicken farms and the ammonia, nitrogen, and phosphate they emit jeopardize the health of these freshwater environments. The pollution from chicken farms can cause algal blooms that kill fish and other aquatic animals and make water dangerous to use.

Air pollution

Chicken farms produce a large quantity of ammonia and nitrogen, much of which is released into the air, with some making its way into waterways causing algal blooms and threatening wildlife. Chemicals such as nitrous oxide and methane contribute to climate change, and are 25 times and 300 times more potent than carbon dioxide at trapping heat in the atmosphere, respectively. The combined effects of air pollution from chicken farms can cause a significant public health issue for local residents.11

How profitable is a chicken farm?

Chickens have been genetically modified through intense breeding programs to maximize profit at great cost to the welfare of the birds themselves. Farms are overcrowded to further maximize profit, often making it impossible for birds to engage in their natural behaviors. On top of the suffering endured by the birds, the chicken farming industry places employees in dangerous situations with low pay. The profit being made by the handful of corporations that have outcompeted smaller farmers is based upon cruelty, subsidies, a disregard for human, animal, and environmental welfare, and an overall lack of any ethical framework.

Chicken farming is often not profitable for individual farmers, but instead locks them into a cycle of debt that they cannot escape. Chicken farming is profitable for the massive corporations that exploit farmers, poultry, and the environment, who extract value from cruel conditions and externalize their costs. Heritage poultry farming represents an alternative method of farming with chickens whose higher welfare genetics require higher welfare conditions. Heritage poultry farming can be more profitable for farmers, better for the environment, and kinder to the birds, but its products are more expensive and not widely available for most people.


The egg and chicken meat industries are characterized by the suffering of birds, people, and the environment. Choosing to reduce, or eliminate, our individual consumption of chicken and eggs is one of the most powerful, and practical, stands we can take to voice our dissatisfaction with the status quo.



For more on this topic, see Kurt Snibbe, “Here’s a look at egg production in the U.S. and other egg facts,” (Orange County Register, April 2, 2021),


USDA, “Poultry – Production and Value, 2020 Summary” (USDA, April 2021),


AVMA, “Welfare Implications of Induced Molting of Layer Chickens” (AVMA, February 2010),


Heng-wei Cheng, “Current Developments in Beak Trimming” (USDA, Fall 2010),


Olanrewaju H.A., Miller W.W., Maslin W.R., et al., “Interactive effects of ammonia and light intensity on ocular, fear and leg health in broiler chickens,” International Journal of Poultry Science 6(10):762-9, 2007,


Kristensen H.H. and Wathes C.M., “Ammonia and poultry welfare: a review,” World’s Poultry Science Journal 56:235-45, 2000.


Olkowski, A.A.”Pathophysiology of Heart Failure in Broiler Chickens: Structural, Biochemical, and Molecular Characteristics,” Poultry Science, 86:5, pgs. 999-1005, May 1 2007, . See also Jean E. Sander, “Sudden Death Syndrome of Broiler Chickens: Flip-Over Disease, Acute Death Syndrome, Dead in Good Condition,” Merck Veterinary Manual, Oct 2022,


E. G. Granquist, G. Vasdal, I. C. de Jong, and R. O. Moe, “Lameness and its relationship with health and production measures in broiler chickens,” Animal, 13:10, pgs. 2365-2372, Oct 2019, See also Arda Aydin, “Leg Weaknesses and Lameness Assessment Methods in Broiler Chickens,” Archives of Animal Husbandry & Dairy Science, 1:2, Dec 2018,


Käthe Elise Kittelson et al., “A Descriptive Study of Keel Bone Fractures in Hens and Roosters from Four Non-Commercial Laying Breeds Housing in Furnished Cages,” Animals 10, no. 11 (November 2020),


Hall et al., “Environmental Injustice and Industrial Chicken Farming in Maryland,” International Journal of Environmental Research and Public Health 18, no. 21 (October 2021),


Leah Baskin-Graves et al., “Rapid Health Impact Assessment of a Proposed Poultry Processing Plant in Millsboro, Delaware,” International Journal of Environmental Research and Public Health 16, no. 18 (September 2019),