Biosecurity can be defined as the variety of protocols utilized to protect swine against transmission of infectious agents between and among herds.
A biosecurity program is multi-faceted and can be broken down into four main categories: site, personnel, animals and transportation. Within each category, there are many factors that need to be a part of a thorough biosecurity program tailored to your system’s needs. With the transition to spring — and the temperature swings and damp weather it brings — it’s important to remember that diseases such as porcine reproductive and respiratory syndrome or TGE can thrive and move around more easily. Transport biosecurity is always an important piece to any overall biosecurity program and it presents many considerations.
When it comes to animal transport and disease transmission, each situation needs to be addressed uniquely. So to start, it’s important to evaluate your system’s needs. The biosecurity level might vary if you are hauling weaned pigs or replacement gilts versus second-cut market hogs or cull animals. If protocols already exist, you need to evaluate them and then audit those protocols to see if they are being executed properly.
For example, a big challenge in assessing cleanliness lies within its inherent subjectivity. One person’s idea of “clean” might differ dramatically from another person’s assessment. Educating workers on your detailed expectations is required to successfully implement a transport biosecurity program. Make sure you are getting what you are asking for, and if not, find out why not. The person in charge of biosecurity for your system should work not only with farm staff but also with the truck drivers that haul your hogs to define cleanliness protocols and expectations. This requires not just verbal discussions but actual in-field training. Everyone involved in the animal loading and transport process needs to train their eyes to see “clean” the same way.
Next, a key step is locating available truck-washes and auditing them to determine if they meet your needs and sanitation criteria. Not all truck-washes are equipped to provide thorough cleaning and disinfecting to meet your needs.
For example, to attain a thorough washing and disinfection of your trailer you need the:
Ability to get the trailer fully cleaned and free of organic material (including space to pull wind-boards).
Availability of disinfectant.
Ability to get the trailer dry.
Ability to wash and disinfect holding compartments, equipment, floor mats and gear shift.
Other factors to consider when choosing a truck-wash include good lighting, adequate space inside the wash bay necessary to get wind-boards pulled, fresh water availability, disinfectant availability and concentration, and drying bays or burner availability. Click here to find available effective truck-washes in your area.
Once your program has been established, you need to monitor and audit it routinely. I have found it helpful to dedicate one person to this job, who is trained on the expectations, to ensure that it is getting done in a timely manner. This provides consistency and clarity among everyone involved. There are various methods that you can use to monitor cleaning and disinfection protocols.
First, there is the visual inspection. This should be part of every monitoring program, as it is a quick way to assess cleanliness and address potential weaknesses on the spot. Also, by routinely inspecting trailers it helps emphasize the importance you place on washing expectations. There are inherent disadvantages to using a visual inspection alone. Visual inspections are subjective, and overall cleanliness does not directly correlate to the trailer being free of pathogens. This is why visual inspections, though an important and necessary part, may not be the only monitoring method that you need to use.
Next, using bacterial swabs is a tool to assist in monitoring. To use this option, you need to develop a standardized sampling method to include the location and size of the sampling area. This information can then be used to calculate the aerobic bacterial count per square centimeter. The recommended level is 1 cfu/cm2 as a general target for disinfection. Unlike the visual inspection, swabs will give you a more objective way to assess the overall cleaning and disinfection by providing you with quantitative values. Some of the disadvantages to using bacterial swabs are that a swab tests for only bacteria (no viruses) and only those that grow on the media used. The biggest disadvantage is that the swabs are not a real-time reading; it takes 48 hours for the cultures to grow and potentially longer to ascertain results if shipping is required.
Third, there have been rapid tests used to assess cleanliness. These tests are designed for slaughter plants, and veterinarians have extrapolated their use on trailers. There are two tests that have been used and researched to evaluate efficacy beyond their primary means.
The Lightning test (BioControl Systems, Bellevue, Wash.) quantifies residual ATP found in bacteria, organic debris and feces using a luminometer.
The other test is the BioClean test (BioVet, St. Anthony, Minn.), which quantifies residual protein on a surface using a color-changing reaction.
The primary advantage is that these tests provide real-time results. The Lightning test displays a score 11 seconds after the surface sample is obtained. The BioClean test can be prepared in 1 minute and results are available in 20 minutes. Besides the initial upfront costs associated with the tests, there are other disadvantages to these tests and their sensitivity and specificity on transport surfaces.
One study by Jason Kelly, DVM, Suidae Health and Production, Algona, Iowa, and his colleagues found that residual manure and feed interfered with the Lightning test’s accuracy and residual disinfectant. Low bacterial protein levels interfered with BioClean’s test accuracy. The inability for these tests to be accurate on transport surfaces renders them functionally useless for that purpose.
Last, serology can be used in specific circumstances to help evaluate and monitor transport protocols. For example, if you routinely move overstocked animals from one site to another, it is imperative that the trailer be cleaned thoroughly. If there were a biosecurity breakdown in transport at this point, it would have a negative impact on the feeder-to-finish production phase. A variety of serology protocols can be implemented on target pathogens of interest. Serology will provide objective data that can help evaluate potential biosecurity weaknesses and opportunities. The disadvantage is that it is limited to certain pathogens, and transport cannot solely be implicated if a positive result is obtained.
Transport biosecurity is a crucial part to any operation’s total biosecurity program. It is an important job to evaluate and implement appropriate protocols for your system’s needs. Most importantly, everyone involved, including farm staff and truck drivers, must be educated on biosecurity expectations so that they understand and build an appreciation for the importance of the various protocols.
Once a transport biosecurity program is in place, routine monitoring is necessary to ensure proper execution. The best monitoring strategy is one involving a variety of methods applicable to your system. Work with your veterinarian to help you develop a plan that works best with your overall transport and biosecurity program.