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USDA NAHMS Swine Study

By Diane DeWitte, Swine Extension Educator. Originally printed in The LAND – March 6/March 13, 2020

I recently saw a commercial on television encouraging me to participate in the upcoming 2020 Census, the count taken every ten years to determine our US population numbers and to collect demographic data. This is the Census year and undoubtedly we will all be asked to provide information about ourselves and our households. The USDA Ag Census is taken every five years, in those years ending in 2 or 7. The agriculture census recently has yielded a lot of important information about the age of our farming community, and the participation by female operators and immigrant farmers.

There’s an additional type of census that’s taken place in agriculture since 1983 which has a tremendous impact on perspectives of livestock health in the United States. Conducted by the United States Department of Agriculture (USDA) this study takes an in-depth look at livestock operations, their management and their health. USDA’s Animal and Plant Health Inspection Service (APHIS) oversees the National Animal Health Monitoring System (NAHMS). NAHMS works with the National Ag Statistics Service (NASS) to collect the data and evaluate it.


Many farmers are familiar with NASS and its Minnesota field office in St. Paul. The Minnesota ag statistics office, headed by state ag statistician Dan Lofthus, collects ag statistics and other information from farm operators and agribusinesses across Minnesota. The Minnesota field office issues the Minnesota Weekly Crop Progress and Condition Report through the growing season and monthly during the winter. This crop report follows crop progress and provides weekly temperature and precipitation data. In my previous role as a UM local (county) Extension Educator, I submitted information weekly to the Service to contribute to the aggregation of information that helps predict crop yields and harvest dates. Minnesota’s NASS field office also publishes an annual bulletin, the Minnesota Agricultural Statistics Book, which collects yield data by county and is a source of rental rate information, too. Extension Offices previously had stacks and boxes-full of the MN Ag Statistics book, but today the entire document can be found on the internet at

As earlier mentioned the NASS has additional roles in US agriculture decision-making. National crop and livestock reports have an effect on markets and marketing plans across the country.


NAHMS was formed to collect, analyze, and disseminate data on animal health, management and productivity across the United States. The NAHMS team conducts national studies on the health and health management of US livestock populations. US livestock species sectors, along with the people who work within the industries, use the NAHMS information to meet their information needs.1

NAHMS teams conduct species studies on a rotating schedule. They first collected swine data in 1990, followed by studies again in 1995, 2000, 2006, and 2012. In 2007 they collected information about swine raised in small-scale operations. In the years between these swine studies, they are learning more about health management in Dairy, Beef, Sheep, Equine, Goats, Bison, Cervids, and Aquaculture. Each species is on a rotating schedule which implements a study every 5-6 years on average.

Data collected from previous swine studies can easily be found on the internet at the NAHMS website. The NAHMS Swine Studies website contains data from all previous NAHMS Swine studies, and tremendous information which has been analyzed and distilled to illustrate changes in the swine industry from study to study. Data collected in these studies is strictly confidential and used to generate scientifically based and statistically valid national estimates which can be used for education, research and policy development. 2


This year is the year of the 2020 Census, and it’s also the year for NAHMS’ Swine Study. In preparation for the study launch, USDA-APHIS has been sending out announcements, collaborating with state Departments of Agriculture and university Extension programs to get the word out. Most recently, the University of Minnesota swine team, along with APHIS veterinarians, discussed the Study with pig farmers who visited the Minnesota Pork Congress in January.

The actual Swine Study will be conducted from July 2020 through January 2021. In June 2020, selected producers will be mailed a letter describing the study and be provide a questionnaire to be completed and returned. Selected producers who don’t respond will be called by a NASS representative to arrange a convenient time to complete the questionnaire via telephone interview.

Participation in the Study is voluntary and confidential. The privacy of every participant is protected, and only those people collecting study data know the identity of respondents. No name or contact information will ever be associated with individual data, and no data will ever be reported in a way that could reveal the identity of a participant. Data are presented only in an aggregate or summary manner.3


The 2020 NAHMS Swine Study has been developed to address two specific types of pig farms. Divided into the “Large Enterprise Study” and the “Small Enterprise Study” the two will collect different types of information based on the size of the operation.

Large Enterprise Study: This survey will take an in-depth look at US swine operations with 1000 or more pigs. Approximately 2700 swine farms will be selected from 13 states. These states, Minnesota, Iowa, North Carolina, Illinois, Indiana, Ohio, Pennsylvania, Michigan, Missouri, South Dakota, Nebraska, Kansas and Oklahoma represent 90% of the US hog operations with 1000 or more pigs.

The objectives of this large study were developed through discussion and surveys within the swine industry, including focus groups populated with representatives from the National Pork Board (NPB), the National Pork Producers Council (NPPC), and the American Association of Swine Veterinarians (AASV). Much of the information collected in this survey will assist the industry in disease management and preparedness strategies to protect the swine industry.

This study of large pig farms will
  • Describe current US swine production practices related to housing, productivity, biosecurity, and morbidity & mortality prevention.
  • Determine the producer-reported prevalence of select pathogens in weaned market pigs.
  • Describe antimicrobial stewardship and use patterns.
  • Evaluate the presence of select economically important pathogens, and characterize isolated organisms from biological specimens.

Small Enterprise Study: In contrast, this study will collect data from swine operations with fewer than 1000 pigs. The NAHMS team hopes to learn more about the swine health and management practices used on these farms and the alternative marketing strategies they implement.4

Small enterprise swine production is a growing sector of the US swine industry because it’s a primary supplier of many niche-market products. This industry segment is very diverse, and the study hopes to learn more about small-farm health and production practices, movement and mortality on small pig farms, and contrast the differences between small and large pig operations.

For the small swine enterprise study, 5000 swine operations from 38 states will be asked to participate. Interestingly, these 38 states account for 95% of the US pig farms with fewer than 1000 pigs. North Dakota, Wyoming, New Mexico, Nevada, Alaska, Hawaii, and six small urban states in the Northeastern US are the states who do not have a large population of small enterprise swine farms.


Producers who are selected to participate in the 2020 NAHMS Swine study can benefit the swine industry in these ways
  • Provide transparent, credible information on industry practices that will help counter misinformation
  • Assist the US swine industry to understand disease preparedness strengths and vulnerabilities
  • Help policymakers and industry stakeholders make science-based decisions
  • Provide data which can be used by researchers and private enterprise to focus on swine health issues, both large and small
  • Identify educational needs related to health and production on small and large swine farm

The NAHMS Swine team is gearing up to meet and visit with swine producers across the US beginning in the summer of 2020. Producer participation is a great way to provide credible data to researchers, and later in the study, to get some biologics testing of the herd. Data collected in this 2020 Study will provide an unquestionable benchmark for swine production and health in the US, and assist the industry in planning for the future.


  2. USDA-APHIS – NAHMS Swine Studies,

Diane DeWitte is a University of Minnesota Extension Educator focused on swine and based in Mankato. She can be reached at
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