This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.
University of Minnesota researchers Lucas Ferreira, Samira Chatila, Mark Schwartz, Marie Culhane, and Cesar A Corzo take a deeper look at the results of a survey given to drivers as part of a larger study.
Key Points:
- Biosecurity is not a top priority for truck drivers when unloading at the harvest plant facility.
- There is variability in the PPE usage when unloading hogs at the harvest plant.
- After visiting the harvest plant, some trailers are not washed.
- While truck drivers are TQA certified, further training is not often encouraged.
Introduction
Market hog truck drivers play a crucial role in the swine industry since they move between multiple pig sites daily. Biosecurity practices during loading/unloading can influence farm and trailer contamination. However, little is known about the practices implemented during the unloading of pigs at the harvest plant, as well as their knowledge regarding biosecurity and the risk of contamination, given that a contaminated trailer has the potential to disseminate pathogens across farms. Therefore, determining driver practices during market hog unloading is crucial to address gaps in the industry regarding biosecurity practices. In this study, we assess how market hog truck drivers unload pigs at the harvest facility.
Methods
As part of a larger study focused on assessing trailer contamination during market hog unloading at a harvest plant, truck drivers were engaged through a survey administered at a Midwestern U.S. harvest facility over the course of one year. A convenience sample of 182 drivers was performed in the study in which each driver answered a questionnaire. Metadata on trailer origin, sanitation practices before and after unloading, trailer destination, and driver/plant employee interaction with the trailer during unloading were recorded. The questionnaires were conducted by two researchers, with one of them conducting the majority of the interviews.
Results
When arriving at the harvest facility, some drivers changed into unloading/loading dedicated shoes and/or clothes after leaving the tractor cab and before entering the lairage area. All drivers wore either rubber boots (92.5%) or regular shoes (7.5%). Some drivers (16.2%) also wore disposable plastic booties (7.7%) or shoe covers (8.5%) over their footwear. A total of 57.8% of the drivers used fabric coveralls, 13.1% used disposable coveralls, 22.4% used pants/long-sleeved shirts, and 6.7% used shorts and short-sleeved shirts/t-shirts. Most drivers (85.9%) wore fabric gloves, while 7.2% used latex gloves and 6.9% wore no hand protection. The PPE combination, or lack thereof, that a driver wore varied between the previously described categories. The most common combination (49.1%) was the use of rubber boots, fabric coveralls, and fabric gloves. When 112 drivers were asked why they chose to use the PPE they were currently wearing, 38.4% reported that it is to stay clean, 26.8% of them reported that they did not know why, 3.6% reported they used it for both comfort and to stay clean, 9.8% reported it as comfort only, 1.8% reported that it was because they were required to and 9.8% reported that it was for other reasons. Only 9.8% of the drivers responded that these were for biosecurity-related reasons.
| Years | Number of truck drivers | Percentage (%) |
| 0 – 1.5 | 6 | 5.6 |
| > 1.5 – 3 | 9 | 8.5 |
| > 3 – 5 | 22 | 20.8 |
| > 5 – 10 | 18 | 17.0 |
| > 10 – 15 | 16 | 15.1 |
| > 15 – 20 | 8 | 7.5 |
| > 20 – 30 | 12 | 11.3 |
| 30 + | 15 | 14.2 |
Among all participating interviewed, the time they had been hauling pigs varied. The majority of them said they worked as truck drivers between 3 and 20 years (Table 1), with 61.8% of the drivers reporting that they had not received any formal training outside of the required transport quality assurance (TQA). Most drivers communicated that they learn and were trained by fellow truck drivers or by the truck companies’ staff. This was said to only encompass a couple of hours and only provided when they started working as drivers hauling pigs. When asked if they washed the trailer before loading the current load they were about to unload, 18.8% of the drivers reported that the trailer had not been washed. When asked whether they had plans to wash the trailer after unloading market hogs, 13.4% of the drivers were not planning to wash the trailer. When washing the trailers, more than half (54.6%) reported that they would wash their trailer with only water, without any disinfectant or disinfection protocol.
Drivers were also asked whether they would haul more than one species in their trailer. In 21.6% of the times, the truck driver reported that they would haul both pigs and cattle using the same trailer weekly.
Discussion
These results show that biosecurity procedures during market hog unloading at the harvest plant facility are variable. It is concerning that only a small proportion of drivers (9.8%) understand that the role PPE is for biosecurity purposes which agrees with the fact that an important number of drivers did not underwent any formal training besides the TQA, showcasing the importance of training and educational opportunities within this group. This study highlights an opportunity for the industry in that trailer sanitation does not occur after visiting the harvest plant and when it occurs, the process may not involve disinfectants or proper cleaning and disinfection protocols. Furthermore, given that approximately a fifth (21.6%) of the trailers are used to haul multi-species calls for investigation on the risk of this practices as it may expose both species to different pathogens that can cause important losses for the respective industries and may represent a risk for human health.
This study was funded by the Swine Health Information Center (SHIC), the University of Minnesota Swine Disease Eradication Center (SDEC), and the American Association of Swine Veterinarians (AASV) Foundation.