SHIC Wean-to-Harvest Program Supports PRRS Biosecurity Enhancement for Fall Season

The Swine Health Information Center, along with the Foundation for Food & Agriculture Research and the Pork Checkoff, launched the Wean-to-Harvest Biosecurity Research Program in the fall of 2022. Goals of the research program were to investigate cost-effective, innovative technologies, protocols, and ideas to enhance biosecurity implementation during the wean-to-harvest phases of swine production. Results received to date provide opportunities for US pork producers to understand potential risks, identify steps to prevent PRRS transmission, and make changes to immediately enhance their herd biosecurity as the fall respiratory disease season approaches.  

At wean-to-harvest sites, biosecurity practices remain inconsistent and less rigorously enforced than at sow or boar stud sites, increasing the risk for disease introduction and transmission. The Wean-to-Harvest Biosecurity Research Program addresses several key biosecurity areas, including bioexclusion (keeping disease off the farm), biocontainment (keeping disease on the farm after an outbreak to lessen risk to neighbors), and transportation biosecurity. A total of 24 projects have been funded through this program to provide a comprehensive approach to advancing biosecurity of US farms. The Wean-to-Harvest Research Program reflects SHIC’s responsiveness to an identified swine health vulnerability and its collaborative efforts to leverage producer Checkoff dollars to safeguard the health of the US swine herd. 

Projects focusing on disease introduction risks, using PRRSV as one of the targeted pathogens at wean-to-harvest sites, have identified key knowledge and tools that producers and veterinarians can apply at the farm today to combat PRRS transmission and introduction into the herd. Outcomes relevant for fall biosecurity are summarized here from two projects, including an industry-wide assessment of bioexclusion practices led by Dr. Gustavo Silva and an assessment of manure pumping effects on disease onset led by Dr. Daniel Linhares, both at Iowa State University.  

Investigations of factors influencing the risks of disease introduction and transmission at wean-to-harvest sites and during transportation have provided key takeaways informing biosecurity enhancement for PRRS management and control: 

1. Biosecurity practices at nursery sites reduced the likelihood of reporting a PRRSV outbreak by 92% compared to finisher sites. 
2. Simple, cost-effective measures such as bench entry, where employees change footwear or clothing before entering different areas, reduce risk of PRRSV spread. 
3. Layering biosecurity practices, such as implementing showers combined with bench entry, can work together to reduce the risk of pathogen contamination through additive barriers. 
4. The likelihood of a PRRSV outbreak is greater when employees cohabit but are employed at differing locations.  
5. Monitoring PRRSV status before and after transportation of swine could decrease the likelihood of a PRRS outbreak as hauling pigs with unknown PRRS status poses on-farm transmission risks.  
6. Washing trucks between loads of weaned piglets significantly reduces the likelihood of a PRRS outbreak, and the combination of washing trucks and downtime between loads is even more effective.  
7. Manure pumping and land application is a risk for PRRSV introduction into farms, with the risk being higher when manure is near nursery sites compared to grow-finish sites. 
8. The risk of PRRSV introduction through a manure pumping event increased if conducted on a site where pigs had been placed for less than 16 weeks. 
9. Monitoring PRRS status through testing oral fluids in wean-to-harvest populations is a useful tool for detecting the virus around manure application. 

Read more about these projects by searching for 23-029 and 23-031 on this page. 

PRRS remains an industry-wide swine health challenge, and as emerging variants continue to be detected in the US, identifying risks and implementing biosecurity steps to prevent the introduction and spread of the virus are critically important. Proactively enhancing wean-to-harvest biosecurity can assist in the control of emerging and endemic diseases across the US pork industry. 

While the Wean-to-Harvest Biosecurity Research Program is no longer accepting new applications, many projects are ongoing, and outcomes will be published as soon as they become available for stakeholder awareness and application on-farm. SHIC continues to invite research proposal submissions that address its five strategic pillars and priorities outlined within the 2025 Plan of Work, spanning multiple facets of swine health. Targeted research on key priority areas, such as biosecurity for wean-to-harvest production, provide knowledge for identifying emerging threats and solutions to reduce impact on pork producers.  

Foundation for Food & Agriculture Research 

The Foundation for Food & Agriculture Research (FFAR) builds public-private partnerships to fund bold research addressing big food and agriculture challenges. FFAR was established in the 2014 Farm Bill to increase public agriculture research investments, fill knowledge gaps and complement the U.S. Department Agriculture’s research agenda. FFAR’s model matches federal funding from Congress with private funding, delivering a powerful return on taxpayer investment. Through collaboration and partnerships, FFAR advances actionable science benefiting farmers, consumers and the environment. 

Swine Health Information Center 

The Swine Health Information Center, launched in 2015 with Pork Checkoff funding, protects and enhances the health of the US swine herd by minimizing the impact of emerging disease threats through preparedness, coordinated communications, global disease monitoring, analysis of swine health data, and targeted research investments. As a conduit of information and research, SHIC encourages sharing of its publications and research. Forward, reprint, and quote SHIC material freely. For more information, visit http://www.swinehealth.org or contact Dr. Megan Niederwerder at [email protected] or Dr. Lisa Becton at [email protected].