Factory farming


Factory farming: Factory farming is a system of livestock farming in which animals are kept in confinement at high-stocking density. Factory farming is an effort to yield the highest output at the lowest cost, and techniques vary around the world.

Animal feeding operation (AFO): An AFO is a facility that raises animals in a confined area void of grass or vegetation for 45 days or more per year.

Concentrated animal feeding operation (CAFO): A CAFO is an AFO that has 1,000 animals or more. CAFOs make up 15% of AFOs.

Animal welfare: The Humane Methods of Slaughter Act, passed in 1958, is enforced by the U.S. Department of Agriculture's (USDA) Food Safety and Inspection Service and ensures the humane slaughter and handling of livestock. While cattle, sheep, and pigs are protected, poultry, fish, and rabbits are not included under this law.

In February 1966, LIFE magazine published a photography spread entitled, "Concentration Camps for Lost and Stolen Pets." The photos by Stan Wayman were taken when the photographer accompanied Frank McMahon, chief investigator of the Humane Society of the United States, onto the property of an animal dealer. The pictures depicted the poor conditions in which animals were bred and sparked public outrage.

The Animal Welfare Act (AWA) of 1966 was signed in part due to the outcry created among the public over the photo spread in LIFE magazine. The original AWA was designed to regulate the treatment of animals, specifically cats and dogs, in research projects. The AWA has since been amended six times.

In 1964 Ruth Harrison, a leading British animal welfare activist and author, published Animal Machines to expose the treatment of animals in farming practices. The British government set up the Farm Animal Welfare Advisory Committee (FAWAC), which recommended the five freedoms of animal welfare. These include the following freedoms: from thirst and hunger; from discomfort; from pain, injury, and disease; from fear and distress; and to express normal behavior. The recommendations were never put into law, however. The Federal Animal Welfare Council was set up in 1979 to replace the FAWAC.

Much of the effort of animal rights activists in the United States in the 1970s focused on the treatment of animals used in laboratory testing.

Through the1980s and into the 1990s, the animal rights movement continued to grow. Included in these developments in Europe were a minimum size for hen cages and a ban on the use of leg-hold traps. In Britain, enclosures for calves raised for veal must have sufficient space for the animal to turn around without difficulty. Sweden mandated that farms must maintain an environment that is as natural as possible. In the United States, campaigns by Farm Animal Reform Movement and People for the Ethical Treatment of Animals have helped increase awareness of inhumane conditions on factory farms.

Today, 54% of animals raised for food in the United States are concentrated on five percent of farms. Cows, hogs, turkeys, and chickens are the most common food animals raised in CAFOs in the United States. By 2008, 34,369 cattle; 9,069,382 chickens; 24,165 thousand ducks; 116,458 hogs; 2,555 sheep and lambs; and 271,625 turkeys were slaughtered for a total of 9.5 billion animals, five times the number of animals slaughtered in 1960.

The USDA's Animal and Plant Health Inspection Service (APHIS) is responsible for enforcing the AWA. The AWA sets minimum standards of care for warm-blooded animals that are bred for commercial sale, used in research, transported commercially, or exhibited in public. However, the act does not include coverage of farm animals raised for food and fiber.

Laws to ensure humane treatment of animals at the state level are few, and do not always apply to farm animals. Both Florida and Arizona have outlawed gestation crates for pigs. According to a 2004 Congressional Research Service Report for Congress on the Humane Treatment of Farm Animals there are few state laws determining treatment for animals on farms.


Animal feeding operation (AFO): An AFO is a facility that raises a large number of animals in a confined area that lacks grass or vegetation for 45 days or more per year. A concentrated animal feeding operation (CAFO) is an AFO that has 1,000 animals or more. Animals are contained in the smallest space possible for their size, and feed is brought to the animals to eliminate the need for pasture or grazing land. These facilities use modern technology whenever possible. According to the U.S. Environmental Protection Agency (EPA), there are about 450,000 AFOs in the United States.

During factory farming, every aspect of animal life and behavior is controlled to ensure that productivity and profits are maximized. The animals are fed inexpensive food that will quickly and effectively increase their size. Females are artificially inseminated rather than mated. Pregnancies are spaced close together to increase production. Mothers and offspring are separated quickly to keep the reproduction process moving. Antibiotics, hormones, and growth-enhancing drugs are given to ensure rapid growth and to prevent infectious diseases.

Antibiotics: Antibiotics are commonly given to farm animals to prevent diseases. According to the Union of Concerned Scientists, livestock in the United States receive 70% of all antimicrobials used in the nation, roughly eight times more than the amount used to treat disease in humans.

Hormones: Hormones such as recombinant bovine growth hormone are used in factory farms (both AFOs and CAFOs) in the United States to promote growth and milk production in cattle, although they are not permitted in pigs or poultry. About 66% of cattle slaughtered in the United States have been injected with growth hormones.

Waste management: There are two ways factory farms manage animal waste: lagoons and sprayfields.

A lagoon is an open-air pit filled with animal urine and manure transferred from facilities using flushing systems or gravity flow gutters. They can be as large as seven acres and contain from 20-45 million gallons of wastewater. Opportunities exist for accidents. If the lagoon is filled too high it may overflow or the lagoon may leak or rupture, filling the surrounding area with raw animal waste.

The second option, used in conjunction with lagoons, is a sprayfield. Manure is pumped out of the lagoons and sprayed onto fields for use as fertilizer.


General: Proponents of factory farming point to the overwhelming economic advantage of the system, that is, food is available at affordable prices. This technique of farming results in a continuous supply of reasonably priced meat, poultry, eggs, milk, and other food products. Furthermore, farmers and ranchers defend their practices, stating that their animals are well taken care of and the animals' needs are adequately addressed.

Some companies in the food industry such as McDonald's, Burger King, and Wendy's have developed guidelines for humane treatment of animals in order to ensure consumers that animal welfare is considered. The National Council of Chain Restaurants began an animal welfare audit program in 2001 to develop more information.

Opponents of factory farms, often animal rights activists, believe that animals in these facilities are treated inhumanely due to the emphasis on profits, efficiency, and productivity. Factory farms are almost completely automated, and there is a diminished role for human-animal interaction. On concentrated animal feeding operations (CAFOs), chicken eggs are collected on conveyor belts and machines dispense food to the animals. As a result, animals that are sick or injured are more likely to be unnoticed.

Hormones: Hormones such as recombinant bovine growth hormone are used to increase cattle growth and milk production. Milk production is increased from 8-17% with the use of growth hormones.

A 1999 report from the European Commission (EC) suggests that eating meat from animals that had been injected with hormones may alter the hormonal balance of humans and may be linked to reproductive issues, as well as breast, prostate, or colon cancer. The hormones examined in the EC report included estradiol, testosterone, progesterone, zeranol, trenbolone, and melengestrol. However, the report concluded that conclusive, comprehensive studies were lacking, and additional research is needed to confirm whether hormone in meat causes cancer.

Currently, importation of beef treated with hormones is prohibited by the European Union. Both the United States and Canada have engaged in an ongoing debate with the European Union over this ban, and appealed to the World Trade Organization (WTO). Both the United States and Canada have studied the use of hormones in animals and found them to be safe. The WTO ruled against the European Union. As a result, both Canada and the United States imposed extra annual trade taxes on goods from the European Union to make up for lost revenue due to the ban on beef.

In May 2009, the EC and the United States came to an agreement in Geneva over the beef hormone dispute. The European Union will import a certain amount of hormone-free beef from the United States. After the first phase of European importation of hormone-free beef the United States will suspend the additional taxes imposed on the European Union.

Hydrogen sulfide: Hydrogen sulfide is a colorless toxic gas that is the result of bacterial breakdown of sulfites, a byproduct of decomposition of manure. This gas may be found in lagoons and sprayfields

Methane gas: Methane is a greenhouse gas that contributes to global warming. According to the U.S. Environmental Protection Agency (EPA), ruminant livestock are responsible for the production of 80 million metric tons of methane annually. Ruminant livestock are animals that have multiple stomachs for the purpose of digestion and include cattle, goats, and sheep. Ruminants are one of the largest sources of methane and account for 20% of methane emissions in the United States.

Nitrate: A chemical compound called nitrogen is commonly found in animal manure. Microorganisms in the environment convert nitrogen into nitrate, a water-soluble plant nutrient.

Lagoons and sprayfields that contain manure may result in nitrate seeping below the root zone and into groundwater. Excessive nitrate concentrations in drinking water may have hazardous effects on human health.

Nitrate is not removed through conventional treatment processes for drinking water. The most common way to reduce nitrate in drinking water is to dilute nitrate-contaminated water with water that has a low-nitrate concentration. The EPA set a maximum contaminant level of 10mg/L for nitrate-nitrogen in drinking water.

Waste management: Factory farms produce nearly two trillion pounds of waste each year. The waste may be reused as fertilizer on sprayfields or it may be stored in. large collections of animal waste known as lagoons. Lagoons may leak or rupture and fill the surrounding area with untreated sewage. Furthermore, lagoons release gases and the stench and toxic chemicals may become airborne, travelling to nearby rural communities. Sprayfields may be coated with more manure than is necessary to fertilize the fields. If the manure is sprayed during rainy or windy periods the manure may run off into rivers and streams. Not only is there the possibility of manure runoff, but also spraying the manure may lead to increased evaporation and vaporization of pollutants.

Current available data suggest that livestock waste management practices may not be adequate or effective to protect water resources. Spills are fairly common. For example, 63% of factory farms in Missouri experienced spills from 1990 to 1994.

Manure may also contain traces of salt and heavy metals, which may end up in bodies of water and accumulate in the sediment, concentrating as they move up the food chain.


General: Concentrated animal feeding operations (CAFOs) may have negative consequences, not only for the animals raised there, but also for workers and nearby residents. These farms may cause air and water pollution in the area of the farm, perhaps extending for miles in every direction. This may result in an increased risk of illness in people who live and work near these facilities.

Animal health: The Pew Commission on Industrial Farm Animal Production, established through the Johns Hopkins Bloomberg School of Public Health, issued a report on industrial farm animal production in 2008. According to the Pew Commission, conditions in CAFOs may be harsh and stressful for the animals. There are no federal regulations to ensure that animals are protected on these farms. The number of animals and the amount of land on which they are housed often exceeds the ability of the land to feed the animals and to absorb the waste produced. These stressful conditions may create an environment in which animals are more susceptible to disease.

Hormones are used to increase cattle growth and milk production. The use of hormones has been shown to cause a 25% increase in bacterial udder infections in cows, leading to treatment with antibiotics.

Antibiotics are used on a large scale to promote animal growth and prevent illness in factory farm animals. Antibiotics may then enter the environment and the food chain, potentially resulting in increased antibiotic-resistant bacteria. Antibiotic-resistant bacteria may have limited response to the currently available drug therapies and lead to increased rates of disease.

Environmental impact: The natural environment may be damaged through factory farming practices. For example, a ruptured lagoon may lead to fish kill, while over-application of manure may lead to the accumulation of nutrients in waterways. Both phosphorous and nitrogen are found in animal manure, and these elements are being found in increased amounts in water sources across the country. An increase in these nutrients in the water may lead to increased algae production, decreased oxygen, and death of aquatic life.

Runoff into streams, rivers, and lakes may also result in large fish kills. In 1995, a waste lagoon burst at a North Carolina hog farm, spilling 25 million gallons of animal waste into a nearby river. As many as 10 million fish were killed and areas were closed off for shellfishing. In 2005 in upstate New York, a manure lagoon burst, spilling three million gallons of liquid manure into a nearby river. Estimates suggested that 200,000-250,000 fish were killed in the spill.

Ruminant animals, including cattle, goats, and sheep, have multiple stomachs for digestion. Ruminants are one of the largest sources of methane gas and account for 20% of methane emissions in the United States. Methane is a greenhouse gas, and thus has an impact on global warming. The concentration of methane in the Earth's atmosphere has increased an estimated 150% since 1750.

Human health: Some early evidence suggests that working on a factory farm or eating foods produced on factory farms may be associated with increased rates of neurological disorders, respiratory disease, miscarriages, bacterial infections, diarrhea, and stomach ailments and other health problems.

There are a number of risks associated with working at a factory farm. Documented injuries to workers are characterized as either fatal or non-fatal. These injuries can be due to machinery or non-machinery issues. Examples of machinery injuries include tractor rollovers, while kicks and bites from animals and workers being pinned between animals and fixed objects are common non-machinery injuries. Injuries that are not machinery related are often the result of inadequate precautions. These injuries are well documented and safety strategies are constantly being implemented to decrease risks and injuries to workers.

Currently, data documenting damage due to air quality are sparse. Concentrated animal feeding operations (CAFOs) may release more gaseous and particulate matter than smaller farm operations. CAFOs generate considerable amounts of manure and other related emissions into both the air and water. The health of workers may be negatively affected by the presence of pollutants such as hydrogen sulfide, ammonia, volatile organic compounds, and endotoxins that are emitted by CAFOs. Gram-negative bacteria produce endotoxins and the endotoxin mixes with agricultural dust particles. Runoff into streams, rivers, and lakes may kill fish and contaminate human drinking water supplies. Factory farms, particularly those raising hogs, are also considered a hazard to air quality and are notorious for their odor problems.

Decomposing manure and other emissions may also lead to negative health effects in residents near CAFOs. The stench may contain harmful chemicals which may contaminate the air supply. Negative effects from these gases include headache, shortness of breath, wheezing, excessive coughing, and diarrhea. Drinking water may also be contaminated.

Of note, most negative effects are related to respiratory health, including nasal allergies, airflow obstruction, and asthma.

Antibiotics are used on a large scale to promote growth and prevent illness in factory farm animals. Antibiotics may enter both the environment and the food chain, potentially resulting in increased antibiotic-resistant bacteria. Antibiotic-resistant bacteria may have limited response to the currently available drug therapies, thereby leading to increased rates of disease. A World Health Organization (WHO) report from 2000 identified food as a major source of antibiotic-resistant disease.

Hydrogen sulfide is a gas that is the result of the bacterial breakdown of manure. Hydrogen sulfide is dangerous, even at low levels. Adverse effects, which are sometimes irreversible, may include sore throat, seizures, and coma. In some cases, it may even cause death.

A chemical compound called nitrogen is commonly found in animal manure. Microorganisms in the environment convert nitrogen into nitrate, a water-soluble plant nutrient.

However, lagoons and sprayfields that contain manure may result in nitrate seeping below the root zone and into groundwater. Excessive consumption of nitrate may result in decreased ability of blood to carry oxygen. Infants are more susceptible to nitrate poisoning, which may result in "blue baby syndrome." Blue baby syndrome is a condition in which decreased oxygen-carrying capacity may lead to a blue coloring of the skin. If untreated, blue baby syndrome may lead to death. Furthermore, high levels of nitrate in drinking water near hog farms have been linked to miscarriages. A 1996 report released by the Centers for Disease Control and Prevention (CDC) described a case study of three women who experienced six miscarriages from 1991 to1993. The women were all from the same area and had been drinking water with high levels of nitrate during their pregnancies, leading investigators to believe there may be a link between nitrate released into the environment and miscarriages.


Regulations for air emissions from concentrated animal feeding operations (CAFOs) have been implemented to prevent injury to farm workers, yet workers continue to report respiratory health symptoms related to their work environments. Therefore, further research is needed to define improved safety strategies to minimize the impact of CAFOs on workers' health.

The Workgroup on Community and Socioeconomic Issues has determined that socioeconomic development and environmental protection must be integrated in order to sustain healthy rural communities. The World Health Organization (WHO) definition of health is the state of complete physical, mental, and social wellbeing and not merely the absence of disease. The consensus statement recommends more stringent criteria for CAFO permits, limiting animal density per watershed area, enhancing local control, and mandating environmental impact statements.

The Pew Commission on Industrial Farm Animal Production, established through the Johns Hopkins Bloomberg School of Public Health, issued a report on industrial farm animal production in 2008. The Commission made six primary recommendations to regulate and improve industrial farm animal production. These recommendations include phasing out and banning the non-therapeutic use of antimicrobials.

The Pew Commission Report concludes that while the current shortcomings of industrial farming are unintentional, the issues of industrial farming need to be addressed to prevent further damage to the environment, to animals, and to public health.

The Conference on Environmental Health Impacts of Concentrated Animal Feeding Operations: Anticipating Hazards, Searching for Solutions is a work group that has identified needs for rigorous monitoring of ecosystems around CAFOs, as well as improvement in defining toxins and chemicals that affect human health and the environment.


This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

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Copyright © 2011 Natural Standard (www.naturalstandard.com)
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