Environmental Stewardship

Pig farmers understand their livelihoods are directly tied to the air, water and land, so they are committed to a sustainable future and recognize that their operations must protect the quality of our planet’s natural resources.

The world’s population is projected to grow to 9-10 billion people by 2050, and that requires global food production to increase 70-80%.1 As food needs rise, pig farmers are working to reduce farming’s impact on the environment and to advance animal agriculture’s environmental and conservation efforts, while also producing more food.

Soil Health and Manure Management

Pig farmers monitor manure output on farms to preserve air and water quality, keeping farms safe and pigs healthy. Manure is an effective, organic nutrient source for sustainable crop production that can be used to feed pigs. This valuable organic fertilizer:

  • Increases the soil’s productivity with less runoff
  • Enhances soil bio-diversity, fostering a wide range of species like insects and birds2
  • Offsets the use of commercial fertilizers made from petroleum products
  • Reduces energy use without increasing nitrous oxide emissions3
  • Helps safeguard air and water quality

Agricultural scientists continue to develop innovative methods to apply and reuse animal manure safely and responsibly, such as:

  • Sophisticated manure systems to capture, control and use manure as fertilizer
  • Soil sampling, GPS tracking and other tools to match the manure to crops’ needs
  • Ration adjustments, such as phase feeding, to meet pigs’ nutrient needs while reducing manure output

Reducing the Carbon Footprint

Today’s pig farmers have access to a comprehensive life-cycle assessment to analyze, track and manage their carbon footprint across the entire supply chain. In 2011, the National Pork Board developed the Carbon Footprint Calculator to provide farmers with a tool to estimate the amount of greenhouse gases released from their production sites.4 NPB also offers environmental sustainability toolkits.

In addition, pig farmers increasingly use wind turbines, methane digesters and solar panels to power their farms. Some farmers are now carbon negative and are able to provide energy back to the power grid for use by others in their region. Farms also set aside sections of their land for natural vegetation called buffer strips and tree windbreaks. These improve air, soil and water quality and provide wildlife habitat.

Over the past 50 years, pig farms have reduced their environmental impact by using5:

75.9% less land
25.1% less water
7% less energy
7.7% lower carbon emissions per Lb. of pork

Air Emissions

A 2002 report by the National Academy of Sciences called on the Environmental Protection Agency (EPA) to develop scientifically credible methodologies for estimating emissions from animal feeding operations. In 2005, the EPA announced the Air Emissions Consent Agreement to address emissions from animal farming. Nearly 2,600 animal farms in 42 states, including 1,856 pig farms, signed the voluntary agreement. Additionally, 24 operations, 10 of which were pig farms, participated in the National Air Emissions Monitoring Study (NAEMS).6

Led by Purdue University with EPA oversight, NAEMS monitored the sites in nine states from 2007 to 2009 to measure emissions of particulate matter, ammonia, hydrogen sulfide and volatile organic compounds.7 The study was conducted at pork production facilities in North Carolina, Indiana, Iowa and Oklahoma, and consisted of six finishing sites and four sow farms.8

The EPA is using information gathered in NAEMS, along with other information, to develop emission estimating methodologies for farm operations. The pork industry is investigating whether changes since 2009 in the technological and management practices employed at pork production facilities have a material effect on the suitability of the NAEMS data for modeling emissions today and over the next several years.9

Overall, greenhouse gas emissions from U.S. animal agriculture have remained relatively consistent while protein production has dramatically increased due to improved feed efficiencies, better manure management strategies and efficient use of cropland. Agriculture accounts for 9.39% of U.S. greenhouse gas emissions, and pork production accounts for just 0.46%.10

Low Emissions


Pork production accounts for just 0.46% of U.S. greenhouse gas emissions

Odor Control

Farmers manage air quality and control odors from production facilities to minimize the impact on neighbors and the community. Air quality is important to pig housing, and adequate ventilation prevents the buildup of ammonia, hydrogen sulfide, carbon monoxide, carbon dioxide and methane gasses, as well as particulates and airborne microorganisms that could be harmful to pigs.11 Innovations, such as methane digesters that convert methane in manure into energy, also reduce air emissions and odors.12

Water Quality

Farmers are developing a number of strategies to protect and improve water quality. Evidence suggests improvements in animal and manure management can reduce the nutrient content in lagoons, as well as the amount of ammonia released into the atmosphere.

Animal manure and wastewater can enter water bodies from spills or breaks of manure storage structures (due to accidents or excessive rain, for example), and non-agricultural application of manure to cropland.13 The Clean Water Act requires large animal farms meeting the regulatory definition of Concentrated Animal Feeding Operations (CAFOs) to apply for a permit from the Environmental Protection Agency’s National Pollution Discharge Elimination System (NPDES) if they plan to apply manure to land that discharges to U.S. waters.14 Some states also hold pig farms to a “zero discharge” requirement.

In addition, some states have adopted citing, operational, manure management and manure limitation regulations that apply to pig farms of all sizes.

Sustainability Research Alliance

Research is integral to understanding the impact of pig farming and learning how to improve sustainability practices. The National Pork Board recently joined the United Soybean Board, National Corn Growers Association and Environmental Defense Fund to form the Sustainability Research Alliance, a program that shares research, coordinates new research and communicates results with the organizations’ members.

View All of Our Practices

1 The Food and Agriculture Organization (a specialized agency of the United Nations). Global agriculture towards 2050. http://www.fao.org/fileadmin/templates/wsfs/docs/expert_paper/How_to_Feed_the_World_in_2050.pdf
2 Hilleman P. Fertilizers’ impact on soil health compared. American Society of Agronomy, Oct. 31, 2018. https://www.agronomy.org/science-news/fertilizers-impact-soil-health-compared
3 USDA-ARS National Laboratory for Agriculture and the Environment. Meta-Analysis of Swine Manure and Commercial Fertilizer on Environmental Endpoints and Soil Health pork.org/research/meta-analysis-swine-manure-commercial-fertilizerenvironmental- endpoints-soil-health/

4Michigan State University press release, Live Swine Carbon Footprint Calculator is now available for pork producers, July 7, 2011. https://www.canr.msu.edu/news/live_swine_carbon_footprint_calculator_is_now_available_for_pork_producers
5Retrospective Analysis of US Pork Production from 1960 to 2015 Using LCA. https://www.pork.org/wp-content/uploads/2016/10/16-214-THOMA-final-rpt.pdf. July 7, 2018.
6 NPPC, Air Emissions Consent Agreement. http://nppc.org/issues/issue/air-emissions-consent-agreement/
7 EPA, National Air Emissions Monitoring Study. https://www.epa.gov/afos-air/national-air-emissions-monitoring-study
8 Pork Checkoff, 2018 Special Call. https://www.pork.org/blog/2018-special-call/
9 Pork Checkoff, 2018 Special Call. https://www.pork.org/blog/2018-special-call/
10 Pork Checkoff, Managing Herd Health for a Safe Food Supply. https://www.pork.org/food-safety/managing-herd-health-safe-food-supply/

11 Swine Care Handbook, 2018.
12 Pork Checkoff, Shared Focus on Innovation, 2014. https://www.pork.org/blog/shared-focus-innovation/
13 EPA, Agricultural Animal Production. https://www.epa.gov/agriculture/agricultural-animal-production#CWA

14The definition of “waters of the U.S.” is under debate. https://www.epa.gov/wotus-rule/about-waters-united-states