Preface
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We address the breadth and severity of the suffering and injustices pigs are forced to endure at the hands of humans and also include slaughter counts and slaughter age.
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| Key Points | 9 |
| Counterclaims | 2 |
| Advocacy Notes | 0 |
| Footnotes | 81 |
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Summary
A concise summary of the briefing (see below for citations).
Pigs are sentient beings capable of suffering, and the suffering pigs endure at the hands of humans is unnecessary because humans have no nutritional need for meat.
Globally, more than 2 billion pigs are killed for meat each year. In the United States, 98% of pigs are factory-farmed, and over 121 million are slaughtered annually. Pigs are typically slaughtered at 5-6 months, which is less than 4% of their natural lifespan.
Their exploitation is evident in the widespread injustices they face in farming practices.
- They endure inhumane slaughter methods, including electrocution, gas, bolt guns, and gunshot, alongside painful mutilations like teeth clipping, castration, tail docking, ear notching, and tattooing.
- Their living conditions are harsh, with overcrowded pens, gestation crates, and farrowing crates, leading to high mortality rates and susceptibility to diseases.
- The industry’s selective breeding practices for larger litters and rapid weight gain impose further stress and health issues on pigs.
- Moreover, pigs often face brutal handling, including being beaten and kicked, and suffer during transport under extreme conditions without basic necessities.
Despite claims of humane treatment, the reality is a systemic cruelty toward pigs ending in brutal slaughter at a young age.
Context
Places this topic in its larger context.
The injustices inherent in exploiting non-human animals stem from seeing them as commodities having only instrumental value, lacking any inherent worth apart from their usefulness to humans.
Key Points
This section provides talking points.
Loss of life is an injustice even if done suddenly and painlessly (which it is not).
To take the life of any sentient being is to harm that being by depriving them of opportunities for fulfillment, even if it is done suddenly and painlessly (which it is not, as explained below).
We have no nutritional need for pig meat, so denying pigs their lives is unnecessary, as are the other forms of suffering enumerated here.
Like all farmed animals, pigs are allowed to live just a small fraction of their natural lifespans. They are slaughtered after living 5 to 6 months of a 10 to 12-year lifespan, representing about 5 percent of their natural lifespan.1
All the accepted methods of pig slaughter are inhumane and include electrocution, gas, bolt guns, or gunshot.
In the United States, federal law2 mandates that pigs must be rendered unconscious before slaughter using one of four methods: electrical stunning, chemical gassing, a captive bolt device, or a gunshot.3
Smaller slaughterhouses typically rely on gunshot or captive bolt methods, mid-sized facilities often use electrical stunning, and the largest pork producers in the U.S.—Smithfield Foods, Tyson Foods, and JBS USA—primarily use carbon dioxide (CO2) gas to render pigs unconscious.4
The four methods of stunning allowed in the United States are used in other countries.5
Stunning and Scalding Alive
Pigs are often scalded alive.
Slaughter lines run so quickly, at an average of 960 kills per hour in a single line,6 that often pigs are not properly stunned.7
- As a consequence, some are still conscious when they reach the scalding tanks which remove their hair.8
Note: The USDA is attempting to remove limits on slaughter line speeds.9
Pigs are physically abused during stunning. Investigators have observed pigs “being beaten, shocked, dragged, and improperly stunned…”10
Gas Chambers: Burning and Suffocation
About Gassing
- Increasingly, pigs are slaughtered in carbon dioxide gas chambers rather than conventional slaughterhouses (Humane Slaughter Association).11
- “Gassing pigs is still standard practice among the world’s largest pork producers, not because it’s humane, but because it’s more efficient, allowing for faster slaughterhouse operations” (Sentient Media).12
The Cruelty of Gassing
- Here’s how Sentient Media describes gassing: “For any living being, pig or human, inhaling high concentrations of CO2 is like being burned from the inside out. With each panicked hyperventilation, the pigs draw the toxic fumes deeper into their bodies, simultaneously suffocating from the lack of oxygen and convulsing violently from the abrasive poison being pumped into their lungs (Sentient Media).13
- The gas “acidifies eyes, nostrils, mouths and lungs, meaning the animals feel like they are burning from the inside out for 15-60 seconds or more” (Phillip Lymbery).14
- Gassing “involves lowering pigs into a gas chamber containing CO2, causing them to gasp for breath and hyperventilate, causing pain and panic amongst the terrified animals.”15
Condemnation of Gassing
- The European Food Safety Authority (EFSA) “affirms that CO2 stunning is incompatible with pig welfare at slaughter” (Eurogroup for Animals).16
- A statement issued by Eurogroup for Animals, along with nearly 70 member organizations such as Compassion in World Farming and the RSPCA, urged a shift away from the practice of gassing pigs (Phillip Lymbery).17
Painful mutilations of pigs include teeth clipping, castration, tail docking, ear notching, and tattooing.
Teeth Clipping
Piglets have their sharp “needle teeth” clipped to prevent them from injuring each other when fighting over teats, inducing severe pain in pigs as it would in humans.18
“Piglets whose teeth have been clipped may experience more gum and tongue injuries, and potentially painful inflammation or abscesses of the teeth.”19
Teeth clipping can result in lasting damage. According to the American Veterinary Medical Association, “clipping has been shown to increase behaviors suggestive of discomfort such as ‘chomping.’”20
Castration
Male piglets are castrated, primarily because their flesh can otherwise develop an unpleasant taste and smell.21
Castration of pigs is generally done by making an incision in the scrotum and pulling out the testes, before cutting the spermatic cord.22
In most countries, it is legal to carry out this procedure without an anesthetic in the piglet’s first week of life, despite the fact that this is known to be painful.23
Carrying out castration at an early age is risky because it can lead to incomplete castration and increase the risk of prolapse of the intestine.24
Tail Docking
Pigs often bite each other’s tails when stressed, so some farmers cut off pigs’ tails to prevent this.25
Tail docking can cause acute and possibly chronic pain.26
Though tail docking is thought to reduce the incidence of serious injuries from biting, it does not eliminate them.27
Ear Notching
Ear notching is painful.28
Tattooing
Tattooing involves some degree of pain and is stressful.29
Unlike humans, when pigs are tattooed they are not consenting and don’t understand what’s happening to them.
Pigs are forced to endure cruel living conditions involving crowded pens, gestation crates, and farrowing crates.
Gestation Crates
Pregnant sows are often kept in metal stalls called gestation crates.30
According to a Humane Society report, “Crated sows suffer a number of significant welfare problems, including elevated risk of urinary tract infections, weakened bones, overgrown hooves, lameness, behavioral restriction, and stereotypies.”31
Gestation crates typically measure just 6.5 ft x 2.5 ft, meaning sows are not able to turn around.32
Some larger sows are not even able to lie on their sides (the way pigs normally sleep) in gestation crates.33
Sows often chew on the bars of gestation crates, a sign of boredom and frustration.34
Pigs prefer to relieve themselves a long way from where they eat and sleep, which is impossible when they are confined to crates.35
Gestation crates have been banned in nine US states.36
Gestation crates have been banned or restricted in the EU and Canada.37
Farrowing Crates
A few days before they are due to give birth, sows are moved to farrowing crates.38
Farrowing crates are slightly larger than gestation crates to allow the sow to lie on her side and nurse her piglets.39
Farrowing crates have an additional enclosure attached to prevent piglets from being accidentally crushed by the sow.40
There is no convincing evidence that farrowing crates reduce mortality.41
Crowded Pens
The stress of confinement can lead pigs to exhibit unnatural cannibalistic behavior.42
Slatted floors, often too wide for young pigs and calves, can lead to lameness, as can hard concrete floors for large sows. Additionally, pigs may develop arthritis due to a lack of exercise.43
After being removed from their mothers, piglets are often crowded into pens where they barely have room to move until they reach slaughter weight.44
Pigs suffer from high mortality rates and disease.
Mortality
Mortality rates for pigs are often high, and their bodies are sometimes left in the pens for extended periods.45
African Swine Fever
African swine fever is one example of pigs’ susceptibility to disease because of crowded filthy conditions.46
African Swine Fever has killed around one-fourth of the global pig population after recent outbreaks occurred in China.47 The global pig population is approximately one billion as of 2024.48
Outbreaks of African Swine Fever are a continuing problem. From the initial African Swine Fever outbreak in China on August 3, 2018, to July 1, 2022, a total of 218 outbreaks were reported to the World Animal Health Information System of the World Organization for Animal Health (WOAH).49
African swine fever has an extremely high mortality rate of 95-100 percent in pigs 50
There is no known treatment for African Swine Fever.51
Selective breeding for large litters and weight gain causes stress and can lead to heart and lung problems.
Large Litters
Modern sows have been bred to produce significantly larger litters than their wild counterparts.52
- Wild pigs produce litter sizes from 2 to 8 piglets.53
- The average liter for sized liter from framed pigs is over 12.54
Suckling so many piglets can put immense strain on the sow and cause her to lose body weight.55
Weight Gain
The harm to pigs of selective breeding for weight gain are:
- Pigs have been bred to gain weight so rapidly that they sometimes struggle to support their own body weight.56
- The rapid weight gain from selective breeding of pigs can lead to joint and leg problems.57
- Selective breeding for lean muscle has led to the prevalence of a gene that makes pigs very sensitive to stress.58
Artificial Insemination is invasive, stressful, and denies pigs a natural behavior.
Artificial insemination of pigs rather than natural breeding is common.59
Artificial insemination gives farms more control over the characteristics of the piglets.
Artificial insemination is a stressful procedure60 to which pigs cannot consent. Also, it denies pigs a natural behavior.
Pigs often endure cruel and brutal handling, including being beaten, punched, kicked, shaken, shocked with prods, and left to die.
Multiple investigations conducted by Mercy for Animals and others have recorded pigs being:616263
- punched
- kicked
- beaten
- shouted at
- having their hair pulled out
- violently shaken
- poked in the eyes
- hit with wooden boards.
Rough handling causes many pigs to become non-ambulatory.64
Pigs who cannot move may be beaten, dragged, or shocked with electric prods to move them through the killing line.65
Pigs may be transported in extreme conditions without rest, food, and water.
A Guardian analysis using USDA data revealed that 330,000 die annually in the United States during transportation to a slaughterhouse, and 800,000 pigs are unable to walk upon arrival.66
Pigs are often transported hundreds of miles in extreme temperatures to be slaughtered, which can lead to deaths due to frostbite or heat stress.67
Legally in the United States, pigs can be transported for up to 28 hours at a time with no rest, food, or water.68
Pigs have been left to die after natural disasters.
In the USA, factory-farmed pigs have been left to die in floods following major hurricanes.
In 2018, Hurricane Florence caused an estimated 5,500 pigs to drown in North Carolina alone.69
In 1999, flooding from Hurricane Floyd resulted in the drowning of more than 20,000 pigs (and more than 2 million chickens and turkeys).70
Counterclaims
Responses to some yes but retorts.
Claim: I only eat pigs that are treated and slaughtered humanely.
The production of meat, dairy, and eggs all result in violent slaughter, and all involve other systemic cruelties. This is true no matter what humane-sounding labels are attached to the packaged body parts and reproduction-related secretions that we buy at the grocery store.
This is well-documented in dozens of undercover investigations, as well as sites such as:
Even if farmed animals were treated humanely, which they are not, by slaughtering them while they are young we are denying them opportunities for fulfillment during what would be the rest of their lives.
Claim: As a pig breeder, I know that a happy and healthy pig is in both our interests.
The interests of the pig breeder and the interest of the pig are not generally aligned, and we should not pretend they are.
If the pig breeder took on the interest of the pig, none of the injustices enumerated herein would happen. In short, breeding would not happen.
Supplementary Info
Additional information that may prove useful.
Ninety-eight percent of pigs in the United States are factory farmed.
Using data from the USDA Census of Agriculture and the Environmental Protection Agency’s definition of concentrated animal feeding operations, the Sentience Institute determined that 98 percent of pigs in the USA are factory-farmed71
Globally, nearly 1.3 billion pigs are slaughtered annually.
Over 1.3 billion pigs are slaughtered annually, according to an analysis by the Our World in Data Group using United Nation data.72
In the United States, over 127 million pigs are slaughtered annually.
Over 127 million pigs are slaughter annually in the United States, according to a 2024 analysis by Statista.73
Pigs are typically slaughtered at 5-6 months, which is less than 4 percent of their natural lifespans.
Slaughter age of pigs74
- Slaughter Age: 5-6 Months
- Natural Lifespan: 10-12 Years
- % of Life Lived: ~4 %
Pertinent Quotes:
“Forget the pig is an animal—treat him just like a machine in a factory,” recommended Hog Farm Management in 1976.75
“We tolerate modern hog farming because we’re kept in ignorance of it. If we had a chance to look pigs in the eye, we might have trouble looking at ourselves in the mirror.” (Mark Essig, New York Times)76
“Your pig almost certainly came from a factory farm, no matter what anyone tells you,” so says Matthew Prescott, of the Human Society of the United States, writing in a Washington Post op-ed.77
“The breeding sow should be thought of, and treated as, a valuable piece of machinery whose function is to pump out baby pigs like a sausage machine,” National Hog Farmer advised in 1978.78
Lineage
Lineage
Pigs were domesticated approximately 9,000 years ago from various subspecies of the Eurasian wild boar.79
Domestication occurred separately in Europe and Asia, though there is evidence that interbreeding later took place.80
Pigs were brought to North America by Spanish explorers in the 16th century.81
Further Study
Sources providing a deeper understanding of the topic or related topics.
Other Resources
Current Affairs: “Forget They Are an Animal,” August 2022.
One only needs to search for “investigations: pigs suffering on farms” for thousands of results.
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Footnotes
Our sources, with links back to where they’re used.
- “Age of Animals Slaughtered,” Farm Transparency Project, October 12, 2017 ↩︎
- “Humane Slaughter Act, Pub. L. No. 85–765, 862. Accessed December 3, 2019.Is Carbon Dioxide Stunning of Pigs Humane?,” RSPCA Knowledge base, 2016. ↩︎
- Higher Welfare Method for Stunning Pigs Gains Ground, American Welfare Institute. 2016. ↩︎
- Higher Welfare Method for Stunning Pigs Gains Ground, American Welfare Institute. 2016. ↩︎
- “Techniques and hygiene practices in slaughtering and meat handling“, FAO ↩︎
- Animal Legal Defense Fund. “Stopping Cruel High-Speed Pig Slaughter,” April 5, 2018 ↩︎
- “Hormel: USDA-Approved High-Speed Slaughter Hell. ↩︎
- “Hormel: USDA-Approved High-Speed Slaughter Hell,” Animal Outlook ↩︎
- Animal Legal Defense Fund. “Stopping Cruel High-Speed Pig Slaughter,” April 5, 2018 ↩︎
- “Hormel: USDA-Approved High-Speed Slaughter Hell,” Animal Outlook ↩︎
- “The Stunning and Killing of Pigs“, Humane Slaughter Association, May 2007 ↩︎
- Matthew Zampa, “There’s Nothing “Humane” About Killing Pigs in Gas Chambers,” Sentient Media, November 12, 2019 ↩︎
- Matthew Zampa, “There’s Nothing “Humane” About Killing Pigs in Gas Chambers,” Sentient Media, November 12, 2019 ↩︎
- “Is Gas Killing the Pig Industry’s Darkest Secret?“, Phillip Lymbery, November 11, 2021 ↩︎
- Compassion in World Farming, “PROMISING NEWS FOR EUROPE’S PIGS, November 13, 2020″ ↩︎
- “EFSA (finally) affirms that CO2 stunning is incompatible with pig welfare at slaughter“, Eurogroup for Animals, June 17, 2017 ↩︎
- “Is Gas Killing the Pig Industry’s Darkest Secret?“, Phillip Lymbery, November 11, 2021 ↩︎
- Hay, M. “Long-Term Detrimental Effects of Tooth Clipping or Grinding in Piglets: A Histological Approach.” Animal Welfare 13 (2004) ↩︎
- “Welfare Implications of Teeth Clipping, Tail Docking and Permanent Identification of Piglets,” American Veterinary Medical Association (AVMA), July 15, 2014. ↩︎
- “Welfare Implications of Teeth Clipping, Tail Docking and Permanent Identification of Piglets,” American Veterinary Medical Association (AVMA), July 15, 2014. ↩︎
- Prunier, A. “A Review of the Welfare Consequences of Surgical Castration in Piglets and the Evaluation of Non-Surgical Methods.” Animal Welfare, no. 15 (2006): 277–89 ↩︎
- Prunier, A. “A Review of the Welfare Consequences of Surgical Castration in Piglets and the Evaluation of Non-Surgical Methods.” Animal Welfare, no. 15 (2006): 277–89 ↩︎
- Prunier, A. “A Review of the Welfare Consequences of Surgical Castration in Piglets and the Evaluation of Non-Surgical Methods.” Animal Welfare, no. 15 (2006): 277–89 ↩︎
- Prunier, A. “A Review of the Welfare Consequences of Surgical Castration in Piglets and the Evaluation of Non-Surgical Methods.” Animal Welfare, no. 15 (2006): 277–89 ↩︎
- Herskin, M. S., K. Thodberg, and H. E. Jensen. “Effects of Tail Docking and Docking Length on Neuroanatomical Changes in Healed Tail Tips of Pigs.” Animal 9, no. 4 (April 2015): 677–81 ↩︎
- Herskin, M. S., K. Thodberg, and H. E. Jensen. “Effects of Tail Docking and Docking Length on Neuroanatomical Changes in Healed Tail Tips of Pigs.” Animal 9, no. 4 (April 2015): 677–81 ↩︎
- Harley, S, La Boyle, Ne O’Connell, Sj More, Dl Teixeira, and A Hanlon. “Docking the Value of Pigmeat? Prevalence and Financial Implications of Welfare Lesions in Irish Slaughter Pigs.” Animal Welfare 23, no. 3 (August 1, 2014): 275–85. ↩︎
- S. Torrey, N. Devillers, M. Lessard, C. Farmer, T. Widowski, Effect of age on the behavioral and physiological responses of piglets to tail docking and ear notching, Journal of Animal Science, Volume 87, Issue 5, May 2009, Pages 1778–1786 ↩︎
- Brach, E.J., B.S. Scobie, and D.P. Raymond. “Hog Tattooing Techniques.” Journal of Agricultural Engineering Research 41, no. 4 (December 1988): 339–44. ↩︎
- John McGlone, “Gestation Stall Design and Space: Care of Pregnant Sows in Individual Gestation Housing,” National Pork Board ↩︎
- HSUS. An HSUS Report: Welfare Issues with Gestation Crates for Pregnant Sows. Humane Society of the United States, 2013. Accessed January 1, 2025. ↩︎
- “Welfare Implications of Gestation Sow Housing,” American Veterinary Medical Association (AVMA), November 19, 2015 ↩︎
- “Welfare Implications of Gestation Sow Housing,” American Veterinary Medical Association (AVMA), November 19, 2015 ↩︎
- Cronin, G. M., P. R. Wiepkema, and J. M. van Ree. “Andorphins Implicated in Stereotypies of Tethred Sows.” Experientia 42, no. 2 (February 1986): 198–99 ↩︎
- “Opinion of the Scientific Panel on Animal Health and Welfare (AHAW) on a Request from the Commission Related to Welfare of Weaners and Rearing Pigs: Effects of Different Space Allowances and Floor.” The EFSA Journal 268 (October 28, 2005): 1–19. ↩︎
- Humane Society International. “Canada Bans Lifelong Confinement for Pigs in Controversial Gestation Crates,” March 6, 2014. ↩︎
- Humane Society International. “Canada Bans Lifelong Confinement for Pigs in Controversial Gestation Crates,” March 6, 2014. ↩︎
- Aland, Andres, and Thomas Banhazi, eds. Livestock Housing: Modern Management to Ensure Optimal Health and Welfare of Farm Animals. The Netherlands: Wageningen Academic Publishers, 2013. ↩︎
- Aland, Andres, and Thomas Banhazi, eds. Livestock Housing: Modern Management to Ensure Optimal Health and Welfare of Farm Animals. The Netherlands: Wageningen Academic Publishers, 2013. ↩︎
- Aland, Andres, and Thomas Banhazi, eds. Livestock Housing: Modern Management to Ensure Optimal Health and Welfare of Farm Animals. The Netherlands: Wageningen Academic Publishers, 2013. ↩︎
- Aland, Andres, and Thomas Banhazi, eds. Livestock Housing: Modern Management to Ensure Optimal Health and Welfare of Farm Animals. The Netherlands: Wageningen Academic Publishers, 2013. ↩︎
- Fox, Michael. “Factory Farming.” The Humane Society Institute for Science and Policy, 1980 ↩︎
- Fox, Michael. “Factory Farming.” The Humane Society Institute for Science and Policy, 1980 ↩︎
- Fox, Michael. “Factory Farming.” The Humane Society Institute for Science and Policy, 1980 ↩︎
- Viva! Campaigns’ 2019 Investigation into Hogwood Pig Farm.” Viva!, August 14, 2019. ↩︎
- Štukelj, Marina, and Jan Plut. “A Review of African Swine Fever – Disease That Is Now a Big Concern in Europe.” Contemporary Agriculture 67, no. 2 (July 1, 2018): 110–18. ↩︎
- The one-forth number is as of 2019, the latest year for which we could find these numbers. Nguyen-Thi, Thinh, et al. “An Assessment of the Economic Impacts of the 2019 African Swine Fever Outbreaks in Vietnam.” Frontiers in Veterinary Science, vol. 8, 25 Oct. 2021. ↩︎
- Worldostats. “Pig Population by Country 2024 – Worldostats.” World of Stats, 13 July 2024, worldostats.com/pig-population-by-country-2024/. Accessed 2 Jan. 2025. ↩︎
- United Nations FAO. The Impact of Disasters on Agriculture and Food Security 2023. 13 Oct. 2023, www.fao.org/3/cc7900en/cc7900en.pdf. Accessed 2 Jan. 2025. ↩︎
- Štukelj, Marina, and Jan Plut. “A Review of African Swine Fever – Disease That Is Now a Big Concern in Europe.” Contemporary Agriculture 67, no. 2 (July 1, 2018): 110–18. ↩︎
- Štukelj, Marina, and Jan Plut. “A Review of African Swine Fever – Disease That Is Now a Big Concern in Europe.” Contemporary Agriculture 67, no. 2 (July 1, 2018): 110–18. ↩︎
- Fonseca, Carlos, António Alves da Silva, Joana Alves, José Vingada, and Amadeu M. V. M. Soares. “Reproductive Performance of Wild Boar Females in Portugal.” European Journal of Wildlife Research 57, no. 2 (April 2011): 363–71. ↩︎
- Fonseca, Carlos, António Alves da Silva, Joana Alves, José Vingada, and Amadeu M. V. M. Soares. “Reproductive Performance of Wild Boar Females in Portugal.” European Journal of Wildlife Research 57, no. 2 (April 2011): 363–71. ↩︎
- Prunier, A., M. Heinonen, and H. Quesnel. “High Physiological Demands in Intensively Raised Pigs: Impact on Health and Welfare.” Animal 4, no. 6 (June 2010): 886–98. ↩︎
- Prunier, A., M. Heinonen, and H. Quesnel. “High Physiological Demands in Intensively Raised Pigs: Impact on Health and Welfare.” Animal 4, no. 6 (June 2010): 886–98. ↩︎
- Prunier, A., M. Heinonen, and H. Quesnel. “High Physiological Demands in Intensively Raised Pigs: Impact on Health and Welfare.” Animal 4, no. 6 (June 2010): 886–98. ↩︎
- Prunier, A., M. Heinonen, and H. Quesnel. “High Physiological Demands in Intensively Raised Pigs: Impact on Health and Welfare.” Animal 4, no. 6 (June 2010): 886–98. ↩︎
- Prunier, A., M. Heinonen, and H. Quesnel. “High Physiological Demands in Intensively Raised Pigs: Impact on Health and Welfare.” Animal 4, no. 6 (June 2010): 886–98. ↩︎
- National Hog Farmer. “Proper AI Techniques, Semen Handling,” October 15, 2007. ↩︎
- Grandin, Temple. “Reduce Stress of Handling to Improve Productivity of Livestock.” Veterinary Medicine, June 198 ↩︎
- “WATCH: Criminal Animal Abuse Caught on Video at Walmart Pork Supplier,” Mercy for Animals, May 6, 2015 ↩︎
- One can find numerous pig abuse videos from multiple sources with this search ↩︎
- “The Horrifying Truth About Pig Farms,” NowThis February 25, 2020 ↩︎
- Ritter, M.J., M. Ellis, N.L. Berry, S.E. Curtis, L. Anil, E. Berg, M. Benjamin, et al. “Review : Transport Losses in Market Weight Pigs: I. A Review of Definitions, Incidence, and Economic Impact.” The Professional Animal Scientist 25, no. 4 (August 2009): 404–14 ↩︎
- “Hormel: USDA-Approved High-Speed Slaughter Hell,” Animal Outlook ↩︎
- Kevany, Sophie. “More than 20 Million Farm Animals Die on Way to Abattoir in US Every Year.” The Guardian, 15 June 2022. Accessed 2 Jan. 2025. ↩︎
- Grandin, T. “The Welfare of Pigs during Transport and Slaughter.” Pig News and Information 24, no. 3 (2003): 83–90 ↩︎
- Garcia, Arlene, Glenna Pirner, Guilherme Picinin, Matthew May, Kimberly Guay, Brittany Backus, Mhairi Sutherland, and John McGlone. “Effect of Provision of Feed and Water during Transport on the Welfare of Weaned Pigs.” Animals 5, no. 2 (June 4, 2015): 407–25. ↩︎
- “The Hidden Victims of Hurricane Florence, Compassion in World Farming, September 26, 2018 ↩︎
- “The Hidden Victims of Hurricane Florence, Compassion in World Farming, September 26, 2018 ↩︎
- “US Factory Farming Estimates.” Sentience Institute. Accessed 2022-06-23 ↩︎
- The annual number was calculated by multiplying the daily number by 365. Roser, Max. “How Many Animals Get Slaughtered Every Day?” Our World in Data, 26 Sept. 2023. Accessed 2 Jan. 2025. ↩︎
- Shahbandeh, M. “Number of Hogs Slaughtered in the U.S. 2019.” Statista, 17 June 2024, www.statista.com/statistics/194382/number-of-hogs-slaughtered-in-the-us-since-2000/. Accessed 2 Jan. 2025. ↩︎
- Age of Animals Slaughtered.” Farm Transparency Project, October 12, 2017 ↩︎
- Marina Bolotnikova provided solid visual evidence for this quote in “Forget They Are an Animal”, Current Affairs, August 2022 ↩︎
- Mark Essig, New York Times. Opinion Guest Essay. Pig Farming Doesn’t Have to Be This Cruel. Dec 16, 2021. ↩︎
- Matthew Prescott, “Your pig almost certainly came from a factory farm, no matter what anyone tells you,” Washington Post op-ed, July 15, 2014 ↩︎
- Marina Bolotnikova provided solid visual evidence for this quote in “Forget They Are an Animal”, Current Affairs, August 2022 ↩︎
- Giuffra, E., J. M. Kijas, V. Amarger, O. Carlborg, J. T. Jeon, and L. Andersson. “The Origin of the Domestic Pig: Independent Domestication and Subsequent Introgression.” Genetics 154, no. 4 (April 2000): 1785–91. ↩︎
- Larson, G. “Worldwide Phylogeography of Wild Boar Reveals Multiple Centers of Pig Domestication.” Science 307, no. 5715 (March 11, 2005): 1618–21. ↩︎
- Vann, Mick. “A History of Pigs in America.” Austinchronicle.com, 2009, www.austinchronicle.com/food/2009-04-10/764573/. Accessed 2 Jan. 2025. ↩︎
