Discussion
As the US feed supply becomes increasingly globalized, the risk of foreign animal diseases entering the country are significantly increased, particularly when dealing with agricultural trade commodities from countries endemically infected with foreign animal diseases. Although expanding international trade allows access to diverse and competitive trade markets, the loss in direct oversight reduces commodity quality control and safety. Therefore, based on the growing body of evidence regarding the ability of foreign animal disease pathogens such as ASFV to survive in feed, it is imperative that swine feed ingredients imported into the US from endemically infected countries be treated with increased scrutiny and caution (Patterson, Niederwerder & Dee, 2019). Obviously, this presents an immeasurable challenge for US CBP due to the sheer volume of imported products and the vast number of seaports in the US. In the absence of unlimited resources, it is important to focus on areas where the risk of disease entry is the highest. In response to this challenge, we conducted this analysis to provide information on the importation of high-risk ingredients from ASFV-positive countries and the corresponding POE. Based on volume of imports, we focused on a country from Asia (China) and one from Eastern Europe (the Ukraine), identified where soy-based products entered the US, and evaluated change in volume and seaport utilization over time. Regarding China, it was interesting to see the consistency of POE utilization and how imports of soy-based products decreased, particularly from 2018 to 2019. When seeking an explanation for this change, the US Soy industry reported that drivers of change were peer-reviewed publications demonstrating the survival of viruses in soy-based products, the resulting swine industry-driven trade press sharing this information and the response from producer stakeholders (P. Lobo, personal communication, July 10, 2020). Of significant impact was a letter written by the National Pork Producers Council to the US Secretary of Agriculture, signed by all major pork-producing states, requested assistance via the Animal Health Protection Act to prohibit soy-based imports from China (NPPC, 2020). In contrast, seaport utilization involving Ukraine imports was inconsistent and volumes imported remained high, which showcased the ability of our approach to identify new areas of risk which had previously gone unnoticed.
Despite these strengths, this approach was not without limitations. Table 1 describes eight specific 10-digit HTS codes that were selected to be included in this study based on their potential to both harbor viable virus and be fed to pigs; however, each of these products do not share the same amount of risk to the US swine population. For example, of these eight specific products, only soybeans, soy-oil cake, and soybean meal are significant risks in terms of both their likelihood to be fed to pigs, and their documented ability to enhance survival of ASFV for extended periods. These products were also deemed high risk because they are major components of swine rations throughout the industry. Another limitation of the approach was the lack of information on final product destination or intended use; therefore, it was not possible to determine how much of a product ultimately ends up in the domestic swine supply chain. In addition, the numbers presented in this study indicated the total volume of a specific product cleared by US Customs at POE. USITC defines these products as “imports for consumption,” intended for use and distribution across all industries and markets and did not provide any further information on final product destination or intended use; therefore, our methods could not determine how much of a product ultimately ends up in the domestic swine supply chain. Furthermore, given the enormous interconnected web that is the modern global trade network, there remains some speculation of the true origin of trade products as they arrive on US shores. For example, countries may import products from one country, only to repackage them and export to another. Therefore, these data are limited to only the immediate importing country and it is not capable to determine complete travel histories of all products that clear US Customs.
In closing, we felt that the exercise was successful and enhanced the knowledge of the topic. We set out to answer four specific questions using a novel approach which gathered information that is important for the development of science-based feed biosecurity plans. While we focused on soy-based products and ASFV-positive countries, this same approach could be applied to multiple foreign trade commodities, which could assist in the development of both human and animal food safety protocols. It is hoped that these efforts will continue to stimulate communication and collaboration between the feed and livestock industries, resulting in further research into the emerging concept of “global feed biosecurity”. Ideally, current and future information regarding the risk of pathogen spread in feed will enhance the accuracy of risk assessments, drive the continual development of efficacious feed-based mitigation strategies, and ultimately bring the health status in the country of origin into the forefront of philosophies regarding the global trade of feed ingredients.
Acknowledgements: Dr. Dee would like to dedicate this paper to the late Dr. Carlos Pijoan, a beloved teacher, mentor, and scientist who would have thoroughly enjoyed debating this topic!
Conflict of Interest: The authors report no conflicts of interest.
Ethical approval: No animals were used in this project.
Data availability statement: All data from the study were made available in the paper.