Market haul sanitation is not a one-size-fits-all solution, says Megan Niederwerder, executive director of Swine Health Information Center (SHIC).
In a study funded by the Swine Health Information Center Wean-to-Harvest Biosecurity Research Program, researchers aimed to understand how different levels of trailer washing impact the spread of porcine epidemic diarrhea virus (PEDV).
The goals of the study were to determine the best practices that balance disease control and economic feasibility across different swine production scenarios. Jim Lowe, DVM, and Ben Blair, DVM, with the University of Illinois College of Veterinary Medicine led the project that determined the necessary level of market haul trailer cleaning depends on PEDV prevalence and system connectivity.
“These insights can help producers develop tailored cleaning protocols that enhance swine health and productivity while effectively managing costs,” SHIC says in a recent report.
The transmission of PEDV within swine production systems poses significant challenges, particularly through market haul trailers transporting pigs between wean-to-finish farms and slaughter facilities, the researchers say.
How Did the Study Work?
This study looked at the most effective and cost-efficient way to clean market haul trailers transporting these pigs to reduce PEDV transmission while balancing economic feasibility.
Two system types were evaluated using computer simulations to model swine production systems under various conditions. The first scenario focused on a single production system with 24,000 sows across eight sites. The second scenario evaluated a region with 24,000 sows divided into four geographically related systems but operationally independent.
Simulations evaluated how washing different proportions of trailers at a consistent washing efficacy rate would affect the spread of PEDV. Scenarios were conducted with PEDV prevalence levels ranging from low (5%), moderate (10%) and high (20%) to see how PEDV prevalence impacted the effectiveness of trailer washing on disease reduction, the report says.
Production was set to occur at fixed rates and under fixed time constraints, with wean-to-finish farms taking two weeks to fill and six weeks to empty completely, resulting in a 22-week turn. SHIC explains that the total costs per scenario included PEDV-infection related expenses and operational costs for truck washing.
The Value of Trailer Decontamination
Overall results show significant reductions in PEDV transmission with increased trailer decontamination. In the single production system scenario, washing 100% of trailers significantly reduced the number of infected farms, with an average of 23 infected premises. Washing 60% of trailers was identified as a cost-effective strategy for the single production system, achieving a significant reduction in disease spread at a lower cost of about $32,956 per farm.
In geographically related systems, washing 100% of trailers significantly reduced the number of infected farms, with an average of 10.5 infected premises, SHIC reports. Surprisingly, researchers found washing 0% of trailers was found to be the most cost-effective in these segregated systems, costing about $25,664 per farm.
What do these findings suggest? Extensive decontamination might not always be necessary in such segregated systems with dedicated transport.
In addition to the 10% PEDV prevalence rate utilized in the referenced results above, high (20%) and low (5%) PEDV prevalence rates were also evaluated, the researchers explain. In scenarios with high PEDV prevalence, it was necessary to wash 80% of trailers to achieve a significant reduction in the number of infected farms at a cost of $48,957 per farm. In low prevalence scenarios, washing trailers were not required to optimize costs, which dropped to $26,862 per farm.
“Cleaning market haul trailers is crucial for controlling the spread of PEDV, but the extent of washing needed can vary,” the report says. “For interconnected systems or during high PEDV prevalence periods, thorough washing of all trailers is essential. However, in more isolated systems or when PEDV prevalence is low, producers may save costs without compromising biosecurity by washing fewer trailers.”
Additional biosecurity that could help include:
• Performing an assessment of current biosecurity measures with a focus on areas of improvement
• Tailoring decontamination strategies based on disease prevalence in the area considering efficacy and cost
• Adjusting strategies as needed depending on emerging data and best practices
• Engaging with veterinary and biosecurity experts to ensure protocols are science-based and specific to farm conditions
Key Takeaways
“Producers need to evaluate what is the most cost-effective strategy for their specific site or system,” Niederwerder says.
She encourages producers to take an integrated approach, considering disease pressures in their area and the risk from farm to farm for transmission.
“In this specific study, there was a unique consideration of both the cost of the truck wash as well as the cost of having PEDV in your farm,” she says. “These types of analyses are critical for producers to balance the cost of biosecurity with the cost of disease.”
How much can be spent on truck washes that will be cost effective to reduce PEDV? In some cases, she says it may be cost effective to have lower market haul sanitation if the PEDV is very low and the systems aren’t connected as far as transport. But in other cases, when PEDV prevalence is high and the systems are really connected, washing more trucks is still going to be the most cost-effective strategy.
This study was funded by SHIC in partnership with the Foundation for Food & Agriculture Research and Pork Checkoff.
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