Demand for Farmed-Animal Feed Crops Fuels Pesticide Use

The US produces 12 million metric tons of beef annually, making it the world’s largest beef producer. To support these production levels, US producers raise 31 million beef cattle, the vast majority of whom are raised industrially, including many raised in concentrated animal feeding operations (CAFOs) spread across the country.[1]

To meet the challenges of housing and feeding so many intensively-farmed animals, the industry relies on a combination of pharmaceuticals and cheap feed crops—such as corn and soybeans—to maximize the efficiency of their operations. In particular, the shift to high-calorie, cheap corn and soybeans to feed animals has been a game-changer for the meat and dairy industry across the globe. Rather than providing grassland for cattle to graze outdoors, grain-based compound feed allows industrial cattle producers to raise many more animals in indoor confinement. 

To maximize the yields of crops used as animal feed, pesticides are used liberally. A 2022 report by World Animal Protection and the Center for Biological Diversity shows that 235 million pounds of pesticides were sprayed on soy and corn crops used as feed for farmed animals in the US. The investigation examined the use of seven major chemicals primarily used on industrial corn and soybean crops (including glyphosate, atrazine, paraquat, dicamba, 2,4-D, neonicotinoids, and bifenthrin), detailing their contribution to environmental damage, the decline of human and non-human health, and significant negative environmental impacts.[2]

“It is not surprising that the increased use of toxic pesticides on corn and soy has coincided with increasing meat and dairy production,“ says Cameron Harsh, Programs Director, World Animal Protection, US. “Treating farmed animals like commodities for mass production has driven the development and expansion of a system that exploits natural resources and animals at all stages,” says Harsh. 

Along with China, India, and Brazil, the US is now among the top ten pesticide-consuming countries in the world. Contrary to claims that genetically engineered crops can be grown using fewer pesticides, studies have warned that the emergence of pesticide-resistant weeds is driving US feed crop farmers toward “a costly herbicide and insecticide treadmill.”[3] With the global market for the pesticides, herbicides, and fungicides used in feed crop protection poised to reach close to $81 billion by 2028, the use and abuse of pesticides has become an unseen cost of our unsustainable and ever-increasing demand for meat and dairy products.

Pesticide Use is Driven by Unjust Food Systems

The process of converting corn and soybean crop-based animal feed to meat is highly inefficient. For example, only 17–30 calories of beef are generated for every 100 calories of soy and corn that confined cattle consume. But these high-calorie, cheap, easily stored crops are produced in vast quantities across the US and are heavily government subsidized. As a result, soy and corn have become the industry norm for animal feed in CAFOs.

Globally, 80% of soy production and 61% of global corn production are used as farmed animal feed.[4] In the US, over 70% of soybean and one-third of corn crops harvested are used as animal feed, supporting the yearly slaughter of over 10 billion farmed animals each year.

The US is the largest producer, consumer, and exporter of corn in the world. Of the over 90 million acres of corn harvested annually in the US, roughly one-third is used as animal feed, a little more than one-third is used as biofuel, and the remaining roughly one-third goes toward other uses which include high fructose corn syrup and other products for human consumption. Producing calories in the form of corn and using animals to convert them into food calories drastically reduces the amount of food produced per acre for human consumption. One acre of an average Iowa cornfield produces over 15 million calories per year but using those calories for biofuels and animal feed yields only 3 million calories of animal products as food.

The US is also the second largest producer of soy in the world. However, as with corn, the vast majority of US soy is used for animal feed rather than for human consumption. Poultry is the number one farmed animal sector consuming soy, followed by hogs, dairy, beef, and aquaculture.

To meet rising demand for meat and dairy products, genetically engineered corn and soy resistant to industrial agrichemicals have been planted in the US since the 1990s. These genetically engineered crops can withstand application of chemicals that kill weeds and insect pests, allowing for blanket spraying. Over the years, however, this approach has led to the evolution of glyphosate-resistant weeds, which in turn has required increased application of glyphosate and numerous other pesticides, thereby setting off a vicious cycle of events with detrimental impacts. And while the liberal use of pesticides is now ubiquitous in large-scale animal feed crop cultivation, it is estimated that less than 0.1%[5] of conventionally applied pesticides reach targeted crop pests.[6] A large portion of applied pesticides seep into the soil, leach into the water table, and contaminate agroecosystems indiscriminately. 

Pesticide Impacts on Marginalized Communities

In the US, 90% of pesticide use happens in the food and agriculture system. While the general population in the US can become exposed to agricultural pesticides and residues through diet and use of contaminated water, farm owners, farm laborers and their families are particularly vulnerable to direct pesticide exposure and its downstream effects. An estimated 44% of farmworkers worldwide experience symptoms of unintentional, acute pesticide poisoning, reporting headaches, nausea, dizziness, and rashes within 48 hours after contact with agrichemical pesticides.[7]

Due to the demographics of US farm labor, occupational exposure to pesticides in the agricultural industry disproportionately affects BIPOC[i] workers—particularly, Latinx[ii] workers—and communities of low income and wealth. On farms across the US, 83% of workers identify as Hispanic or Latinx.[8] Pesticide use is disproportionately heavier in US counties with higher Latinx populations. These communities are already made vulnerable to occupational hazards and economic exploitation in agriculture by a long history of systematic oppression and structural racism.[9]

The US EPA currently allows the use of 85 pesticides that have been phased out or banned in the EU, China, and Brazil, increasing risks to the health of US farm workers.[10] In 2018, the agriculture sector applied 4.2 million pounds of the pesticide paraquat chloride (paraquat) on corn and soybean crops across the US. Increasingly used to combat the growth of glyphosate-resistant weeds, paraquat is classified as highly hazardous to human health and was banned in the European Union as early as 2007. As of 2020, it has been banned in 53 countries worldwide. In 2021, a class action lawsuit was filed against a major manufacturer of paraquat, alleging that exposure to paraquat has led to hundreds of agricultural workers developing Parkinson’s disease. After considering banning the aerial spraying of paraquat in 2021, the EPA has continued to allow paraquat use with additional safety measures.

There are currently 31 pesticide manufacturing facilities across the US that the EPA has reported to be in “Significant Violation” of environmental laws that include the Clean Water Act and the Clean Air Act. Disturbingly, an average of 44% of the residents within a mile of the 31 pesticide manufacturing facilities had incomes less than two times the federal poverty level, compared to the national average of 28%.

In addition to pesticide exposure during farming activities, BIPOC communities and other marginalized communities are disproportionately impacted by the manufacturing, storage, and disposal of agricultural pesticides. Black and Latinx US residents living below the poverty line are twice as likely to live within a mile of a hazardous chemical facility.[11]

Glyphosate in US Feed Crops  

There are over 400 pesticides used on agriculture crops across the US, and since 2001, the pesticide glyphosate has risen to become the most commonly used pesticide in the country.

Impacts on the Environment

Analysis of USDA data by World Animal Protection and the Center for Biological Diversity shows that in 2018 171.5 million pounds of glyphosate were applied on corn and soybean crops, out of which 100 million pounds are attributed to animal feed production. When applied to crops, glyphosate is almost always combined with other chemicals to enhance its solubility and uptake within crops. However, these formulations also make it easier for glyphosate to enter and accumulate within the larger environment and become parts of interconnected elements and systems that sustain plant and animal life beyond the farm. Over the years, glyphosate has been detected in falling rain,[12] in the air,[13] in irrigation water,[14] and in municipal wastewater treatment,[15] leading to diverse negative impacts on human and animal health.

Impacts on Humans

There are over currently 13,000 lawsuits alleging glyphosate’s role in declining human health. Glyphosate exposure has been linked to adverse human health impacts such as non-Hodgkin lymphoma,[16] hormone disruption,[17] impaired reproductive health,[18] rhinitis,[19] and various neurological disorders including ADHD and autism.[20] In addition to the oral route of entry via food and water consumption, glyphosate can also enter the body via the skin and lungs. Up to 90% of farmers[21] and 80% of the general public—including children—have been shown to have glyphosate present in urine samples. In 2020, glyphosate was detected in the urine samples of 30% of newborn babies studied in Washington and New York, concluding that glyphosate could have entered babies’ bodies via human breast milk, baby formula, contaminated drinking water or even by crossing the placenta.[22]

While the World Health Organization deemed glyphosate a carcinogenic risk to humans in 2015, the US Environmental Protection Agency (EPA) relied partly on non-peer-reviewed studies to conclude that, under the recommended application guidelines, carcinogenic hazards of glyphosate were unlikely.[23]

The EPA also differs from other countries regarding the quantity of ‘acceptable’ amounts of glyphosate that can be ingested daily via food residues. The EPA rules that 1.75 mg of glyphosate per kilogram body weight per day (mg/kg/day) is acceptable,[24] while European guidelines limit residue exposure to just 0.3 mg/kg/day. Acceptable minimal residue levels (MRL) of glyphosate measured in farm products have also been increased over time to allow for higher application of pesticides on industrial soy and corn.[25]

Federal law allows the residue of glyphosate in animal feed to be more than 100 times that permitted on grains consumed directly by humans, equating to higher residues in farmed animal tissues and byproducts. The pesticide residue allowed in red meat is more than 20 times that permitted in most plant foods sold in grocery stores. US regulatory tolerance for pesticide exposure through food reveals the vital role that pesticides play in producing industrial feed crops for CAFOs, enabling high national meat and dairy consumption.

Impacts on Animals

Glyphosate used in the production of animal feed crops contributes directly to animal harm and exploitation by enabling the system of industrial animal farming. In addition, glyphosate impacts farmed animals through ingestion of residues. Safe pesticide exposure levels for animals ingesting residues from feed crops are not typically established. Instead, the assumption is made that conservative estimates for human residue exposure from animal foods will provide adequate controls on farmed animal exposure.[26] However, high concentrations of glyphosate in animal feed have been associated with malformations and infertility in pigs[27] and rats[28] and botulism in cows.[29]

As pesticides are retained in soil and surrounding environments, wild animals and plants are also increasingly affected by pesticide exposure. Glyphosate is moderately to very highly toxic to fish, invertebrates, mammals, and birds, and is likely to adversely affect 93% of species studied by EPA in North America. Glyphosate use may be driving the global decline of amphibians such as tadpoles,[30] and many North American pollinators. Planting of glyphosate-resistant corn and soybeans has largely eradicated milkweed from Midwestern farm fields,[31] spurring the drastic decline of the monarch butterfly.[32] Studies have also documented glyphosate’s damage to marine environments and marine life.[33]

Pesticide Use and Airborne Pollutants

In addition to the use of herbicides and other crop pesticides in feed crop production, the animal agriculture industry applies pesticides to treat insect pests that are present in CAFOs. These include stable flies, blow flies, cattle grubs, scabies, mites, cattle lice, and ticks.[34] In the US alone, 99.8% of all feed yards apply insecticides directly to cattle and feed yard surfaces.[35] The resulting 669,000 kg of airborne insecticide-laden particulate matter generated from one cattle feed yard contained enough insecticides to kill over a billion honeybees daily.[36] Studies indicate that the risks posed by the aerial transport of insecticides emanating from beef cattle feed yards have not been adequately considered and are therefore far less likely to be regulated.   

CAFOs are housed disproportionately in low-income, rural areas of the US. Air pollutant emissions from CAFOs in the US do not always have an odor but carry significant health effects for surrounding communities. However, emissions from CAFOs are unregulated due to a controversial 2005 EPA amnesty deal allowing CAFOs to avoid pollutant standard-setting, monitoring, and enforcement under the Clean Air Act; the Comprehensive Environmental Response, Compensation, and Liability Act; and the Emergency Planning and Community Right-to-Know Act. Under the continuation of the amnesty deal, the vast majority of the 250,000 CAFOs across the US housing 8.7 billion animals continue to be exempt from reporting their air emissions to the EPA.

Conclusion

In December 2021, the EPA reduced the cost to register new pesticides, making it easier for companies to gain approval for new compounds. In early 2022, the Center for Biological Diversity announced its intent to sue the EPA for approving 300 pesticides over the past six years without fully considering potential harm to endangered species. The EPA subsequently announced plans to assess the harm new pesticides may inflict on endangered species and critical habitats before approving their use. However, the more rigorous assessment will only apply to new pesticides and will not impact pesticides already approved for use. 

Pesticide use is inseparable from industrial animal agriculture. Pesticides are an integral part of producing the volume of industrial feed crops necessary to support US industrial animal farming. In the US, 99% of farmed animals live in CAFOs and are fed industrially produced grain and compound feed grown with agricultural pesticides, allowing more than 10 billion industrially raised animals to be killed each year for US consumption.

The harms and injustices connected to pesticide use in animal feed production offer a clear example of the harm caused by a food system that prioritizes agribusiness profits over human, animal, and environmental well-being. The systemic linkage between pesticides and animal farming makes pesticide an important topic for cross-movement collaboration to end the unprecedented harmful exploitation of human and non-human sentient beings through industrial animal farming.

Current industrial animal agriculture necessitates pesticide use, but a food system based around industrial animal production is neither necessary nor inevitable. The majority of pesticide use in the US food system could be made obsolete by shifting prioritization from industrial animal products to sustainable, plant-forward and plant-based human diets. Beans and many other legumes and grains have the potential to ensure global food security without the exploitation of farmed animals or the large-scale production of industrial feed crops. Reducing or replacing demand for meat and dairy foods from industrial animal farming would provide the dual benefit of alleviating the need for high volumes of industrial soy and corn, and dramatically reducing the use of agrichemical pesticides throughout the US food system.

A version of this post appeared previously at Sentient Media on June 15, 2022.


[i] Stray Dog Institute uses the term BIPOC to recognize the lived histories of oppression and resistance experienced by Black, Indigenous, and People of Color. This term is not universally embraced, particularly because it can erase the experiences of individual groups by lumping them together. Additionally, the language of this term reflects the specific historical social context of the United States and may not accurately reflect current or past racial and ethnic descriptions elsewhere. We recognize these drawbacks and use the term BIPOC only when a statement is truly applicable to Black, Indigenous, Latinx, Middle Eastern, North African, East Asian, South Asian, Southeast Asian, and Pacific Islander communities in the US. When an experience or condition is applicable only to a specific group, we use specific rather than general language.

[ii] Stray Dog Institute uses Latinx as a gender-neutral alternative to “Latino” or “Latina” to refer to persons of Latin American heritage living in the US. We use this term although we recognize that it simplifies and homogenizes important cultural variations, and individuals may have their own preferred terminology. We honor the importance of the diverse lived experiences of oppression and unique cultural histories of Latin American countries, regions, and peoples.


[1] “Cattle” (USDA, National Agriculture Statistics Service, July 2022), https://downloads.usda.library.cornell.edu/usda-esmis/files/h702q636h/tq57pz24k/cz30r103f/catl0722.pdf.

[2] Isra Mahmood et al., “Effects of Pesticides on Environment,” in Plant, Soil and Microbes: Volume 1: Implications in Crop Science, ed. Khalid Rehman Hakeem, Mohd Sayeed Akhtar, and Siti Nor Akmar Abdullah (Cham: Springer International Publishing, 2016), 253–69, https://doi.org/10.1007/978-3-319-27455-3_13.

[3] Charles M. Benbrook, “Impacts of Genetically Engineered Crops on Pesticide Use in the U.S. — the First Sixteen Years,” Environmental Sciences Europe 24, no. 1 (September 28, 2012): 24, https://doi.org/10.1186/2190-4715-24-24.

[4] Ulrike Grote et al., “Food Security and the Dynamics of Wheat and Maize Value Chains in Africa and Asia,” Frontiers in Sustainable Food Systems 4 (2021), https://www.frontiersin.org/articles/10.3389/fsufs.2020.617009.

[5] David Pimentel and Michael Burgess, “Small Amounts of Pesticides Reaching Target Insects,” Environment, Development and Sustainability 14, no. 1 (February 1, 2012): 1–2, https://doi.org/10.1007/s10668-011-9325-5.

[6] Rashi Miglani and Satpal Singh Bisht, “World of Earthworms with Pesticides and Insecticides,” Interdisciplinary Toxicology 12, no. 2 (October 2019): 71–82, https://doi.org/10.2478/intox-2019-0008.

[7] Wolfgang Boedeker et al., “The Global Distribution of Acute Unintentional Pesticide Poisoning: Estimations Based on a Systematic Review,” BMC Public Health 20, no. 1 (December 7, 2020): 1875, https://doi.org/10.1186/s12889-020-09939-0.

[8] Nathan Donley et al., “Pesticides and Environmental Injustice in the USA: Root Causes, Current Regulatory Reinforcement and a Path Forward,” BMC Public Health 22 (April 19, 2022): 708, https://doi.org/10.1186/s12889-022-13057-4.

[9] See endnote 8.

[10] Nathan Donley, “The USA Lags behind Other Agricultural Nations in Banning Harmful Pesticides,” Environmental Health 18, no. 1 (June 7, 2019): 44, https://doi.org/10.1186/s12940-019-0488-0.

[11] Amanda Starbuck et al., “Shadow of Danger: Poverty, Race and Unequal Chemical Facility Hazards.” Center for Effective Government (2016), https://www.foreffectivegov.org/shadow-of-danger.

[12] William A. Battaglin. et al., “Glyphosate and its degradation product AMPA occur frequently and widely in U.S. soils, surface water, groundwater, and precipitation,” Journal of American Water Resources Associations 50 (2014): 275-290, https://doi.org/10.1111/jawr.12159.

[13] Feng‐chih Chang et al., “Occurrence and fate of the herbicide glyphosate and its degradate aminomethylphosphonic acid in the atmosphere,” Environmental Toxicology and Chemistry 30 (2011): 548-555,  https://doi.org/10.1002/etc.431.

[14] Marcelo P. Gomes et al., “Emerging contaminants in water used for maize irrigation: Economic and food safety losses associated with ciprofloxacin and glyphosate.” Ecotoxicology and Environmental Safety 196 (2020): 110549, https://doi.org/10.1016/j.ecoenv.2020.110549.

[15] Thomas Poiger et al., “Occurrence of the herbicide glyphosate and its metabolite AMPA in surface waters in Switzerland determined with on-line solid phase extraction LC-MS/MS.” Environmental Science and Pollution Research 24 (2017): 1588-1596, https://doi.org/10.1007/s11356-016-7835-2.

[16] Luoping Zhang et al., “Exposure to Glyphosate-Based Herbicides and Risk for Non-Hodgkin Lymphoma: A Meta-Analysis and Supporting Evidence,” Mutation Research. Reviews in Mutation Research 781 (2019): 186–206, https://doi.org/10.1016/j.mrrev.2019.02.001.

[17] Céline Gasnier et al., “Glyphosate-Based Herbicides Are Toxic and Endocrine Disruptors in Human Cell Lines,” Toxicology 262, no. 3 (August 21, 2009): 184–91, https://doi.org/10.1016/j.tox.2009.06.006.

[18] Medardo Avila-Vazquez et al., “Environmental Exposure to Glyphosate and Reproductive Health Impacts in Agricultural Population of Argentina,” Journal of Environmental Protection 9, no. 3 (March 19, 2018): 241–53, https://doi.org/10.4236/jep.2018.93016.

[19] Rebecca E. Slager et al., “Rhinitis Associated with Pesticide Exposure among Commercial Pesticide Applicators in the Agricultural Health Study,” Occupational and Environmental Medicine 66, no. 11 (November 2009): 718–24, https://doi.org/10.1136/oem.2008.041798.

[20] Stephanie Seneff, Nancy Swanson, and Chen Li, “Aluminum and Glyphosate Can Synergistically Induce Pineal Gland Pathology: Connection to Gut Dysbiosis and Neurological Disease,” Agricultural Sciences 06, no. 01 (January 8, 2015): 42, https://doi.org/10.4236/as.2015.61005.

[21] John F. Acquavella et al., “Exposure Misclassification in Studies of Agricultural Pesticides: Insights from Biomonitoring,” Epidemiology (Cambridge, Mass.) 17, no. 1 (January 2006): 69–74, https://doi.org/10.1097/01.ede.0000190603.52867.22.

[22] Leonardo Trasande et al., “Glyphosate Exposures and Kidney Injury Biomarkers in Infants and Young Children,” Environmental Pollution 256 (January 1, 2020): 113334, https://doi.org/10.1016/j.envpol.2019.113334.

[23] Charles M. Benbrook, “How Did the US EPA and IARC Reach Diametrically Opposed Conclusions on the Genotoxicity of Glyphosate-Based Herbicides?,” Environmental Sciences Europe 31, no. 1 (January 14, 2019): 2, https://doi.org/10.1186/s12302-018-0184-7.

[24] John Peterson Myers et al., “Concerns over Use of Glyphosate-Based Herbicides and Risks Associated with Exposures: A Consensus Statement,” Environmental Health 15, no. 1 (February 17, 2016): 19, https://doi.org/10.1186/s12940-016-0117-0.

[25] A. H. C. van Bruggen et al., “Indirect Effects of the Herbicide Glyphosate on Plant, Animal and Human Health Through Its Effects on Microbial Communities,” Frontiers in Environmental Science 9 (2021), https://www.frontiersin.org/articles/10.3389/fenvs.2021.763917.

[26] John L Vicini et al., “Glyphosate in Livestock: Feed Residues and Animal Health1,” Journal of Animal Science 97, no. 11 (November 4, 2019): 4509–18, https://doi.org/10.1093/jas/skz295.

[27] Monika Krüger et al., “Detection of glyphosate in malformed piglets.” Journal of Environmental and Analytical Toxicology 4, (2014): 2161-0525, http://dx.doi.org/10.4172/2161-0525.1000230.

[28] Daiane Cattani, et al., “Developmental exposure to glyphosate-based herbicide and depressive-like behavior in adult offspring: Implication of glutamate excitotoxicity and oxidative stress.” Toxicology 387 (2017): 67-80, https://doi.org/10.1016/j.tox.2017.06.001.

[29] Henning Gerlach et al., “Oral Application of Charcoal and Humic Acids to Dairy Cows Influences Clostridium Botulinum Blood Serum Antibody Level and Glyphosate Excretion in Urine,” Journal of Clinical Toxicology 04, no. 02 (2014), https://doi.org/10.4172/2161-0495.1000186.

[30] Rick A. Relyea, “The Lethal Impact of Roundup on Aquatic and Terrestrial Amphibians,” Ecological Applications 15, no. 4 (2005): 1118–24, https://doi.org/10.1890/04-1291.

[31] Wayne E Thogmartin et al., “Restoring Monarch Butterfly Habitat in the Midwestern US: ‘All Hands on Deck,’” Environmental Research Letters 12, no. 7 (July 1, 2017): 074005, https://doi.org/10.1088/1748-9326/aa7637.

[32] John Pleasants, “Milkweed Restoration in the Midwest for Monarch Butterfly Recovery: Estimates of Milkweeds Lost, Milkweeds Remaining and Milkweeds That Must Be Added to Increase the Monarch Population,” Insect Conservation and Diversity 10, no. 1 (2017): 42–53, https://doi.org/10.1111/icad.12198.

[33] Valerio Matozzo, Jacopo Fabrello, and Maria Gabriella Marin, “The Effects of Glyphosate and Its Commercial Formulations to Marine Invertebrates: A Review,” Journal of Marine Science and Engineering 8, no. 6 (June 2020): 399, https://doi.org/10.3390/jmse8060399.

[34] Eric M. Peterson, Frank B. Green, and Philip N. Smith, “Pesticides Used on Beef Cattle Feed Yards Are Aerially Transported into the Environment Via Particulate Matter,” Environmental Science & Technology 54, no. 20 (October 20, 2020): 13008–15, https://doi.org/10.1021/acs.est.0c03603.

[35] “Feedlot 2011”, Part IV (USDA, National Animal Health Monitoring System, 2011) https://www.aphis.usda.gov/animal_health/nahms/feedlot/downloads/feedlot2011/Feed11_dr_PartIV_1.pdf

[36] See endnote 34.

About the author

Stray Dog Institute

To cultivate dignity, justice, and sustainability in the food system, Stray Dog Institute provides nonprofit allies with funding, strategic research, and opportunities for collaboration. Together, we hope to build a more compassionate world for people, animals, and the environment.

About the Author

To cultivate dignity, justice, and sustainability in the food system, Stray Dog Institute provides nonprofit allies with funding, strategic research, and opportunities for collaboration. Together, we hope to build a more compassionate world for people, animals, and the environment.

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