Project #: 23-028 | Principal Investigator: Gustavo Machado | Institution: North Carolina State University | Posted: 1/10/24 | Keywords: Trucks, deliveries, transportation, prevention strategies, and biosecurity
Jason A. Galvis1, Cesar Corzo2 and Gustavo Machado1
1Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA.
2Veterinary Population Medicine Department, College of Veterinary Medicine, University of Minnesota, St Paul, MN, USA
Introduction: Substantial evidence indicates that vehicle movement is closely linked to the spread of diseases among animal production sites. To mitigate these transmission events, vehicles undergo thorough cleaning and disinfection (C&D) procedures. However, C&D effectiveness remains an open-ended question, while the frequency of C&D between farm visits is unknown. Consequently, relying solely on vehicle C&D is insufficient to control the spread of diseases, and supplementary strategies are necessary to prevent disease transmission events via contaminated vehicles. The objective of this study was to reduce the risk of between-farm transmission through vehicle contacts by rerouting vehicles while considering C&D events and effectiveness.
Methodology: We collected movements of 654 vehicles in a pig-dense area in the U.S. and identified vehicles visiting farms, C&D, slaughterhouses, feed mills, and parking locations. Farm data was collected from enhanced on-farm Secure Pork Supply (SPS) biosecurity plans available in the Rapid Access Biosecurity application (RABappTM). We ranked and reorganized the vehicles delivering animals and feed to farms according to several conditions, including disease status of visited farms, vehicle contact network communities, C&D events, and shipment time efficiency. Using these conditions, we simulated vehicle movements for one week, indicating each vehicle was C&D after each shipment. We reconstructed the between-farm contact network by vehicle movements from observed and simulated data and compared i) the number of contacts from PRRSV-positive and PEDV-positive farms to disease-free farms and ii) contacts between farms from different network communities (group of farms densely interconnected). In addition, we calculated the frequency of vehicles visiting C&D stations and traveled distances.
Results: Implementing our rerouting system led to a substantial decrease in the median number of risky contacts among farms (Figure 1). For vehicles transporting feed, risky contacts were reduced by 42% when C&D effectiveness was 0% and 89% when C&D was 50%. For vehicles transporting pigs to market, risky contacts were reduced by 25%, with C&D effectiveness at 0% and 45% with C&D at 50%. Vehicles transporting pigs between farms only showed a remarkable reduction after C&D effectiveness above 50%, with 33% fewer risky contacts. Finally, with C&D effectiveness at 100%, risky contacts dropped below 5% for vehicles transporting feed and pigs to market, and below 37% for vehicles transporting pigs to farms. Our system also reduced the interactions between farms from distinct network communities, 17% when C&D effectiveness was 0%, and 99.9% with C&D effectiveness at 100%. Furthermore, the rerouting system increased by up to 81% in C&D visits and up to 54% in distance traveled per vehicle.
Discussion and conclusion: We showed that by rerouting vehicle movements, risky contacts among farms were reduced. Despite the potential benefit of preventing disease spread, our rerouting system increased the C&D events and the distance traveled per vehicle. Given the severe economic impact of PRRSV, PEDV, ASFV, and other endemic infectious diseases on swine production, the costs and logistics of a vehicle rerouting system require a close examination to justify the potential economic benefits of reducing disease transmission compared to continuing traditional vehicle movement schedules and C&D protocols. Ultimately, our rerouting system could be integrated into regular vehicle shipment schedule operations as an additional tool for preventing and controlling the spread of livestock diseases among farms via the indirect contact network of vehicle movements
Figure 1. Infectious edges within the vehicle contact network. Box plots displaying the number of connections, named infectious edges or risky contact, from PRRSV-positive and PEDV-positive farms to disease-free farms within the vehicle contact network for one week.
Project #: 23-036 | Principal Investigator: Rodger Main, DVM, PhD | Institution: Iowa State University | Posted: 1/10/24 | Keywords: PRRSV, PEDV, Biosecurity, Temperature, Time
Since its introduction in 2013, PEDV remains an important disease to the US swine industry, necessitating robust biosecurity measures. This study aimed to evaluate various cleaning protocols—Positive Control (no cleaning), Dry Clean – Scrape and Bake (TADD), Volume Hose Wash and Disinfect, Power Wash and Disinfect, and Negative Control—to determine their efficacy in mitigating PEDV spread from a contaminated trailer to the farm site area after simulating foot traffic between these two areas.
Livestock trailers were contaminated with PEDV-positive feces, except for the Negative Control using PEDV-negative feces. Different cleaning methods were applied, followed by a simulation to mimic real-world conditions. PEDV presence was quantified using qPCR to measure viral load on trailer surfaces and farm loading areas. Bioassay was conducted to inoculated naïve pigs with samples recovered from the farm site area after applying the treatments on the trailers. Statistical analyses, including ANOVA and Fisher’s Exact test, compared PEDV levels and positive PCR results across treatments.
Washing treatments, particularly volume hose and power wash & disinfect, demonstrated significant efficacy in reducing viral load on both trailer and farm-site surfaces. On farm-site surfaces, these methods achieved over 99% reduction in viral genomic copies compared to the positive control. This marked reduction is crucial in preventing infection of susceptible pigs and highlights the importance of effective washing protocols. The Power Wash and Disinfect method emerged as highly effective, significantly reducing PEDV levels on trailer surfaces with most samples showing negative PCR results (3 of 5). The Volume Hose Wash and Disinfect method also demonstrated substantial efficacy in inactivating the virus on the bioassay, though some residual fecal material was observed. Even though the Scrape and Bake method reduced the viral load in more than (>98%), it was not effective in terms of virus inactivation, where the pigs from four out of five replicates became infected for PEDV on bioassay. All negative control replicates were negative in the qPCR result of the surfaces sampled and remained negative on the bioassay after inoculation.
The findings from this study suggest routinely cleaning and disinfecting all market haul trailers leaving terminal points of concentration by either of the water-based trailer cleaning treatments evaluated present as an opportunity to create a step-change in the magnitude of inter-premises disease transmission associated with market haul transport and elevate the state of preparedness across the US pork industry.
Contact: [email protected]
Project #: 23-051 | Principal Investigators: James F. Lowe, DVM MS | Institution: Lowe Consulting Ltd. | Posted: 12/16/24 | Keywords: Swine biosecurity, Trailer decontamination, Disease transmission, Epidemiological modeling, Cost-benefit analysis
Objectives: The primary goal of this study was to determine the most effective and cost-efficient way to clean market haul trailers that transport pigs between wean-to-finish farms and slaughter facilities. We aimed to understand how different levels of trailer washing impact the spread of Porcine Epidemic Diarrhea virus (PEDv) and to find the best practices that balance disease control and economic feasibility.
Research Conducted: We used computer simulations to model swine production systems under various conditions. The first scenario focused on a single production system with 24,000 sows across 8 sites. The second scenario looked at a region with 24,000 sows divided into 4 systems, each geographically related but otherwise unconnected. We ran simulations to see how washing different percentages of trailers would affect the spread of PEDv. Additionally, we tested scenarios with different PEDv prevalence levels to see how these conditions would change the effectiveness of trailer washing.
Findings: 1. Single Production System:
– Washing 100% of trailers significantly reduced the number of infected farms, with an average of 23.13 infected premises.
– Washing 60% of trailers was identified as a cost-effective strategy, achieving a significant reduction in disease spread at a lower cost of about $32,956 per farm.
2. Geographically Related Systems:
– Washing 100% of trailers in this setup reduced the average number of infected premises to 10.56.
– Surprisingly, washing 0% of trailers was found to be the most cost-effective in these systems, costing about $25,664 per farm, suggesting that extensive decontamination might not always be necessary in such segregated systems.
3. Impact of Disease Prevalence:
– In scenarios with high PEDv prevalence (20%), it was necessary to wash 80% of trailers to achieve a significant reduction in infection, at a cost of $48,957 per farm.
– In low prevalence scenarios (5%), washing trailers was not required to minimize costs, which dropped to $26,862 per farm.
What These Findings Mean for the Industry:
The study shows that cleaning market haul trailers is crucial for controlling the spread of PEDv, but the extent of washing needed can vary. For interconnected systems or during high prevalence periods, thorough washing of trailers is essential. However, in more isolated systems or when disease prevalence is low, producers might save costs without compromising biosecurity by washing fewer trailers. These insights can help producers develop tailored cleaning protocols that enhance swine health and productivity while managing costs effectively.
By adopting these findings, producers can make informed decisions about trailer decontamination practices, ensuring their operations are both economically viable and biosecure. This research provides a practical roadmap for reducing PEDv transmission and safeguarding the health of swine herds.
Project #: SHIC 23-019 | Principal Investigators: Erin Kettelkamp, DVM | Institution: Swine Vet Center | Posted: 6/14/2024 | Keywords:aerosol, biocontainment, biosecurity, fan covering, PRRS, swine
Objective
The primary objective of this study was to evaluate the effectiveness of various rapidly deployable, exhaust fan cover materials in reducing airborne particles that can carry swine respiratory pathogens. These pathogens include viruses such as PRRSv (Porcine Reproductive and Respiratory Syndrome virus), PEDv (Porcine Epidemic Diarrhea virus), and IAV (Influenza A virus). By identifying effective and rapidly deployable fan coverings, we aim to enhance biosecurity measures and reduce the spread of these diseases within and between swine farms.
Research Conducted
The study was conducted at a commercial swine facility, focusing on three types of fan covers: PolyKlean™ synthetic air filter media (Blue Poly), a nylon tear-resistant fan sock (Fan Sock), and a polyethylene privacy screen material (Black Screen). These were compared to fans with no coverings (control). Airborne particle counts were measured using a handheld particle sizer to determine the reduction in particles ranging from 0.3 to 5.0 micrometers (µm). Measurements were taken at various distances from the fans to assess the effectiveness of each covering material. Weather conditions and ventilation settings were carefully monitored and recorded to ensure consistency across all sampling points.
Research Findings
The results showed that the Fan Sock was the most effective in reducing airborne particle quantities (0.7 to 5.0 µm) at 1 meter from the fan compared to the Blue Poly and control treatments, with the Black Screen treatment being intermediate. However, as the distance from the fan increased, differences in particle quantities were not observed across the treatments, resulting in no overall differences.
Implications for the Industry
These findings suggest that implementing exhaust fan coverings can be most beneficial at reducing larger air particles up to short distances (up to 1 meter) from fans. Based on the relationship between air particle size and the spread of airborne swine pathogens, additional research is warranted to understand the role of fan coverings on biocontainment. The fan sock provided better airflow and is already commonly used in the swine industry, making it a more practical option for rapid deployment during disease outbreaks to potentially improve regional biocontainment. Further research is recommended to validate these findings and explore additional biosecurity measures.
Project #: SHIC 23-031 | Principal Investigators: Daniel C. L. Linhares; Gustavo de Sousa e Silva | Institution: Iowa State University College of Veterinary Medicine | Posted: 7/1/2024 | Keywords: Manure; Manure pumping; PRRS; PEDV; Wean-to-finish; Bioexclusion; Biocontainment
Due to its nutritional and fertilizing value to the soil, the pig manure is spread in fields surrounding pig sites for the following grain crop season. However, manure agitation and spreading poses risks to animal health due to the gases and pathogens that may recirculate in the site and surrounding sites. Therefore, the goal of this project was to estimate the impact of manure pumping practices on PRRSV and PEDV health outcomes in wean-to-finish (W2F) pig populations. A retrospective and prospective studies were conducted separately.
The retrospective epidemiological study estimated the odds of PRRSV or PEDV outbreak occurring within four weeks after manure pumping out from the site event (exposure 1) or being located in a field receiving manure at 1-, 3-, and 5-miles from a site (exposure 2). The study population was W2F lots from one production system that pumped manure between July 2020 and December 2022. PRRSV or PEDV outbreaks (cases) were defined based on veterinarian assessment, pathogen detection in tissues, and increased mortality rate after the pumping event or receiving manure from other site. For the analyses, controls were selected to match spatially (within 6.2 miles of cases) and temporally (placement dates within a 4-week interval from outbreak dates) cases. The analyses revealed that the odds of PRRSV outbreaks events within a 4-week following pumping out of the site and spreading manure activities were higher. Additionally, nurseries had higher odds of reporting a PRRSV outbreak following pumping out activities compared to grow-finish. No associations between PEDV outbreak and manure practices were detected in this retrospective study.
The prospective study assessed the frequency of PRRSV RNA and PEDV RNA detection in pit samples from midwestern W2F barns and the likelihood of increasing PCR-positivity of pig oral fluids after manure pumping. The population of interest was wean-to-finish lots from a swine producer that pumped manure between April 2023 and December 2023. PRRSV and PEDV were tested by PCR on oral fluids and pit manure. All growing pig barns were selected based on the absence of PRRSV or PEDV before the pumping process.
The analyses revealed an increase in the odds of testing PRRSV-positive in oral fluids after pumping out manure. The PEDV positivity in manure was significantly higher than that of PRRSV, however there was no increase in oral fluids PEDV-positivity after pumping manure. Anyways, there was evidence of both PRRSV and PEDV virus in manure samples, confirming the ecological importance of manure in viral spread within and between sites.
Both studies (retrospective and prospective) showed that manure pumping practices were associated with PRRSV outbreak and spread. The odds of a PRRSV outbreak within a 4-week window were greater when the site was pumped and was in close proximity to a field receiving manure. The odds of a previously PRRSV-negative barn becoming PRRSV-positive increased significantly after manure pumping. This information enables veterinarians and producers to justify strategies for biosecurity and biocontainment associated with pumping manure out of sites or when a site is near a field receiving manure.
Project #: SHIC 23-037 | Principal Investigators: Daniel Linhares & Edison Magalhães | Institution: Iowa State University College of Veterinary Medicine | Posted: 6/11/2024 | Keywords: market pigs; trailer sanitation; automated; data integration; compliance verification
The pilot project aimed to address the challenge of documenting truck washes between visits to slaughterhouses and return to swine barns, a critical aspect of market haul sanitation in the swine industry. The primary goal was to assess three different methods for automatically recording truck wash events and market pig deliveries at packing plants, thus, enabling producers to verify trailer cleanliness compliance. Furthermore, automated reports were produced to inform the decision-makers on the status of the trailers, and identify the non-compliance events (i.e., trailers not washed between loads to the packing plant).
The project was conducted in collaboration with one swine producer in the US Midwestern region, focusing on evaluating the feasibility and effectiveness of different technologies in recording truck-related events. Three approaches were tested: GPS tracking of trucks and trailers; a software application (APP) for automatically creating electronic tickets of washing events; and manual data collection at truck wash and packing plant sites. The research team collected and analyzed data over a specified period to evaluate the accuracy and reliability of each method.
The findings revealed that while all three methods had their strengths and limitations, GPS-based tracking showed higher accuracy in documenting truck wash events and deliveries at packing plants compared to the other methods. However, GPS-based methods were susceptible to errors such as false or duplicate events and the geofence limits are not adjusted, highlighting the importance of optimizing technology parameters to minimize discrepancies. On the other hand, despite the CleanTrailer APP having a slightly inferior performance for recording truck wash events, it provided an electronic ticket with pictures of before and after the wash, providing additional information beyond the electronic wash ticket. Despite some missed washes, the agreement between GPS data and the CleanTrailer APP was generally high, indicating the potential of automated systems in ensuring compliance with sanitation standards.
The results of this pilot study have significant implications for the swine industry, as providing producers with automated reports to monitor truck wash compliance. The scalability of the methods tested suggests broader applicability across production systems, offering a standardized approach to monitoring market haul sanitation practices. Ultimately, these findings empower producers to make informed decisions regarding truck sanitation, thereby safeguarding animal health and improving overall industry practices.
Project #: SHIC 23-071 | Principal Investigator: Dr. Michael Chetta | Institution: Talent Metrics Consulting | Posted: 5/16/2024 | Keywords: safety, biosecurity, biocontainment, wean-to-market, caretaker, mitigation, prevention, preparedness, compliance
The Swine Health Information Center has identified that caretaker motivation related to compliance with biosecurity behaviors is a priority needing to be better understood. An exploratory study was conducted to establish a baseline for worker motivation and identify possible issues within the industry that could be impacting compliance with biosecurity. This research and measurement related to motivation is the first of its kind in the industry and sets the groundwork for better understanding the primary factors influencing worker motivation and compliance.
Initial findings suggest the swine industry’s problem with biosecurity compliance is not a motivationally driven issue, and not wholly influenced in the way initially conceptualized and measured. There is strong support that biosecurity compliance is influenced by job resources (specifically supervisor support), availability of performance feedback and rewards. Additionally, the analyses suggest workers are heavily impacted in doing their work and adhering to biosecurity protocols by physical workload and demanding contact with animals.
There is reason to believe that motivation can be assessed differently and that the impact of training and measuring the implementation/effectiveness of biosecurity procedures could yield valuable insights. Continuing this research across the industry will help one of the largest industries in the US to better understand the interactions and motivations behind worker attitudes and perceptions towards biosecurity adherence and to enhance positive outcomes for employees, farms, and consumers.
Project #: SHIC 23-046 | Principal Investigator: Francisco Cabezon, Pipestone Research VP | Institution: Pipestone Research | Posted: 5/16/2024 | Keywords: Power-washing, robotics, cleanliness, water usage, labor
A 2,400 head wean-to-finish barn with two rooms of 1,200 head capacity (196 feet x 50 feet) with 44 pens each was used in the study. A group of nursery pigs were placed in the barn and raised until harvest. The barn was then cleaned, with one room washed using traditional manual power washer methods from a contract service, and the other room cleaned using a railed robotic power washer prototype, followed up with a manual power wash to remove any additional manure (touch-up). The trial consisted of two washing events (August 2023 and February 2024) to compare the efficacy and efficiency of an automated power washer to a manned power-washing crew, based on cleaning time, manpower time, water usage, and cleanliness rate.
In the room washed with the rail robotic power washer prototype, four rails were installed (2 on each side of the room divided by the central hallway) to cover the pen floor and side walls at a maximum height of 10 inches from the slat level. The rail robotic power washer prototype consisted of a trailer head carrying a rotary nozzle connected to a gas power washer. The trailer head was battery powered, and the speed of the trailer on the rail and the speed of rotation of the nozzle could be adjusted. Two different rotary nozzles were tested. The robot power washer with a single rotary nozzle was set to move through the rails at an average speed of 11.0 inches/min, with a nozzle rotation time cycle of 22 seconds (August 2023 data). In the case of the double rotary nozzle, the robotic power washer was set to move at an average speed of 14.8 inches/min, with a nozzle rotation time cycle of 30 seconds (February 2024 data). In both cases, the speed of the trailer head and rotation of the nozzle were adjusted to achieve 2 hits per slat.
Multiple methods were used to evaluate cleanliness (pre-wash, post-wash, and post touch-up): visual assessment, adenosine triphosphate (ATP) measurements to assess organic material, bacterial culture with dip slides, and a reverse-transcriptase real-time PCR (RT-qPCR) for rotavirus detection. There were 12 pens assessed in each room, which were equally spaced throughout the room. Five sites in each pen were assessed: the fencing, floor, wall, waterer, and feeder.
In August 2023 (single rotary nozzle test), total water usage in the robotic power washing room was 8,396 gallons in comparison to 6,211 gallons in the manual power washing room. Total washing time in the robotic power washer room was 22.1 h (13.0 h of robotic washing and 9.1 h of manual touch up washing) in comparison to 10.5 h of manual power washing in the control room. The manual washing labor time in the robotically washed room was reduced 13% (1.4 h), but total washing time was longer by 11.6 h.
In February 2024 (double rotary nozzle data), total water usage in the robotic power washing room was 10,897 gallons in comparison to 7,526 gallons in the manual power washing room. Total washing time in the robotic power washer room was 19.3 h (10.1 h of robotic washing and 9.2 h of manual touch up washing) in comparison to 13.3 h of manual power washing in the control room. In this case, manual washing labor time in the robotically washed room was reduced by 31% (4.1h) with the robot, but overall washing time was longer by 6 h.
Cleaning scores differences before and after washing were significant for each power washer method, at all sites in a pen, and in each testing. The cleanliness trend was from very dirty to clean or very clean. For the robotic power washed room, the post-wash touch-up by the manual power washing team was necessary for the median value to reach the “Very Clean” score.
More bacterial count, rotavirus presence, and ATP levels were found after the washing process for both wash methods. Power washing does not clean the barn, it is solely a means to remove debris and must be followed by a disinfection process. Power washing should be completed to the necessary level to ensure that disinfection can be performed well.
Cleaning expectations of this barn were extremely high, this could explain to some degree the long touch-up process. Robotic power washer cannot easily access the feeders. The washing crew spent considerable time washing the feeders. The number of feeders in the barn will be a limiting factor to the efficiency of the robotic power washer. The barn used for this research has a low pigs/feeder ratio (27 pigs/feeder, doubled 1-hole wet dry feeder). Another limiting factor for the automated power washer is the number of rails and their positioning. In the current study 4 rails were installed in the room. This allowed walls to be washed at a maximum height of 10 inches from the slat level, however, the wash did not cover the central hallway. Additional rails could increase the covered area by the rail power washer, but it would represent additional costs and time of operation.
Although power washing needs at facilities are time and resource intensive, this robotic power-washer prototype does not provide adequate savings in manpower or water usage, so further refinements are needed.
Project #: SHIC 23-018 | Principal Investigator: Dustin Boler, Bailey Harsh | Institution: Carthage Innovative Swine Solutions, University of Illinois | Posted: 11/14/2023 | Keywords: Truck wash biosecurity, ATP bioluminescence, disease monitoring, surveillance
This research evaluated the performance of two adenosine triphosphate (ATP) instruments to estimate cleanliness in livestock trailers. The results of the ATP instruments were compared to aerobic plate counts (bacterial contamination) to determine if ATP bioluminescence could be used as an indicator of trailer cleanliness without the need for visual inspection. ATP is a source of cellular energy that is present among all living organisms. This includes viruses and bacteria that remain after a commercial trailer cleaning. Normally, trailer cleanliness is determined visual evaluation by a person that inspects the trailer to determine if it is free of organic material and suitable to return to a farm. However, studies have demonstrated that visual inspection of cleaned transport trailers may be insufficient to ensure cleanliness and reduce disease transmission risk because viruses and bacteria are microscopic in nature and cannot be seen by the human eye. Further, visual inspection to determine if a trailer is clean usually occurs after the invested cost of propane to dry the truck has occurred. ATP bioluminescence uses a chemical reaction where a swab is used to detect the presence of ATP. The more ATP that is present, the greater the chemical reaction. This technology uses the same chemical process a firefly uses to illuminate. When ATP is exposed to the enzyme a light is produced. The more ATP that is present the brighter the light. The intensity (brightness of the light) is measured in relative light units (RLU). A greater RLU indicates more ATP and reduction in overall cleanliness. So, this technology can be equated to the brightness of a firefly. The brighter a firefly glows; the more ATP is present. In this case, the brighter the swab glows, the more ATP is present, the more potential microbial contamination is present. The goals of this project were to determine the areas of the trailer with the greatest surface contamination, the correlation between microbial counts and RLUs, and the number of locations that need to accurately determine surface cleanliness.
This project evaluated livestock trailers at two commercial trailer washes. One of those locations included trailers that were known to transport livestock from a farm known to be PRRS or PEDv positive. In total, 100 livestock trailers were tested usings biolumiomters to determine the amount of ATP that remained after a commercial trailer wash. Protocols are in place to prevent people from entering a livestock trailer after it has been cleaned to prevent contamination. For this technology to be adopted into practice, locations inside the trailer that are accessible from outside the trailer must be evaluated. This trial evaluated the back door flush gate (BDFG), rear drivers side access door (RSAD), the belly flush gate (BFG), belly side access door (BSAD), nose side access door (NAD).
Figure 1 Back door flush gate. An area of the trailer that is indicative of overall trailer cleanliness.
The results from this study indicated that the areas of highest concern sampled in this study were the nose access door and the back door flush gate as detected both by ATP bioluminescence and APC. A key finding of this research was that nose access door was the area least likely to be adequately cleaned, but only a few trailers actually had nose access doors. Nearly all of the trailers evaluated had a back door flush gate and therefore makes it a logical place to swab a livestock trailer to determine the overall cleanliness.
The ability of ATP to be used as an indicator of trailer cleanliness was dependent on the instrument used, with the 3M machine being more closely correlated with bacterial contamination. Swabs were also collected to determine the presence of PEDv, but all swabs were negative. These data suggest that ATP bioluminometers can be used in livestock trailers to quickly determine the general cleanliness of the trailer without the need for a visual inspection. Bacterial swabs to determine APC levels should also be used to determine the effectiveness of the cleaning protocol.
Copyright 2024 | Swinehealth.org | Website by Heartland Marketing Group