In the U.S., at any given moment, more than 1.7 billion chickens, pigs, cows, and other animals are being raised for food, with more than 10 billion slaughtered each year. Nearly all of them are confined in what the EPA and industry classify as Concentrated Animal Feeding Operations (CAFOs).

Antibiotic use on factory farms

Because animals in industrial confinement are kept in crowded, stressful conditions that accelerate disease spread, antibiotics are routinely administered prophylactically — a practice that fuels antimicrobial resistance (AR). Between 70% - 80% of all antibiotics in the U.S., totaling 15.6 million lbs in 2024, are administered to livestock.

Factory farming fuels global water shortages

Globally, agriculture is the most water-intensive human activity. Around one-third of all agricultural water use is for livestock production, accounting for around 69% of annual global water withdrawals. In the U.S., up to 98% of the water involved in livestock production was used to grow animal feed.

Factory farming is responsible for the pollution and eutrophication of waterways

Animal agriculture is the leading polluter of U.S. rivers and streams, the second-largest source of wetlands contamination, and the third-largest source of lake pollution. Annually, U.S. CAFOs produce around 941 billion pounds of manure, none of which is treated or regulated like human waste.1 This untreated manure can directly contaminate groundwater and lead to the eutrophication of waterways.

Deforestation

According to the FAO, agriculture drives almost 90% of global deforestation. Factory farming accelerates deforestation primarily by creating massive demand for cropland to grow animal feed. Globally, livestock production uses 77% of all agricultural land, but produces less than 20% of the world’s calories. Expanding land used for feed crops, especially soy and corn, is the single largest driver of forest loss in South America.

Calories and protein lost to animal feed

Factory farming wastes vast quantities of human‑edible food by diverting grain and soy into animal feed, causing losses of calories, protein, and environmental resources. Nearly half of the world’s grain never reaches human plates, and in the U.S., around over half of corn and soy is grown for livestock. Because animals inefficiently convert feed, ending grain‑for‑feed use could free enough food to feed up to 2 billion people per year.

Greenhouse gas emissions

Animal agriculture is responsible for 14.5% of all human-made greenhouse gases. Factory farms emit methane and nitrous oxide, which are up to 300 times more damaging as greenhouse gases than carbon dioxide. The IPCC estimates that methane from cattle and manure is responsible for roughly 32% of global anthropogenic methane.

Biodiversity loss

Factory farming is one of the largest drivers of global biodiversity loss via habitat destruction, monoculture expansion, pesticide driven species collapse, water and soil degradation, and climate change. The UN Convention to Combat Desertification (UNCCD) identifies livestock production as “perhaps the single largest driver of biodiversity loss.”

Breeding grounds for the next pandemic

Factory farms contribute to global pandemic risk through creating ideal conditions for pathogen amplification, increasing opportunities for spillover between wildlife, livestock, and humans, and enabling rapid early stage spread once a pathogen emerges. H1N1 (swine flu) and H5N1 (avian influenza) both have links to CAFOs.

Factory farms fuel diet related disease

High consumption of factory farmed meat is linked to colorectal cancer, heart disease, type 2 diabetes, stroke, and kidney disease – some of the leading causes of death worldwide. Large epidemiological studies link the high intake of processed and industrially produced red meat to increased mortality from cardiovascular disease and certain cancers.

Harms to rural communities

Factory farming harms rural communities through pollution, public health impacts, and economic displacement. EPA data show that large CAFOs emit ammonia, hydrogen sulfide, and fine particulates linked to respiratory illness in nearby residents, while CDC research finds higher rates of antibiotic resistant infections in counties with dense livestock operations. Nearby groundwater is also often contaminated with nitrates.