Evaluation of a Water-Based Medium-Expansion Foam Depopulation Method in Suckling and Finisher Pigs.

Abstract

Simple SummaryThe need for effective and efficient means of mass depopulation of swine is critical, given foreign animal diseases, natural disasters, and other hazards that threaten swine production. Mass depopulation methods that can be applied to swine at all ages under field conditions are important due to the varying sizes and differing handling methods across the stages of swine development. The American Veterinary Medical Association Guidelines for Mass Depopulation contain limited options for procedures under constrained circumstances that can be applied rapidly across all sizes of pigs. Previous work has shown that water-based foam can be as effective as carbon dioxide for adult swine depopulation, but without CO2 supply, expensive equipment, and potential human health hazards. The present study demonstrates that water-based foam is also effective for depopulating, in suckling (18 to 24 days) and finisher (63 to 100 days) pigs. When combined with previous findings, water-based foam is a depopulation method that can be applied rapidly and effectively to all ages in the swine production cycle.The threat of foreign animal disease introduction through contaminated animal products, feed ingredients, and wildlife vectors have highlighted the need for additional approved methods for mass depopulation of swine under emergency scenarios, especially methods that can be applied to pigs across all production phases. The market disruption within the swine industry due to the SARS-CoV-2 pandemic has demonstrated this lack of preparation. The objective of this study was to validate water-based foam as a mass depopulation method for suckling (18 to 24 days of age) and finisher stage (63 to 100 days of age) pigs. Finisher pigs (n = 31, originally 32 but one finisher pig died prior to foaming), allocated as 9 triads and 1 set of 4 pigs, in 10 total replicates, and suckling pigs (n = 32), randomly allocated to two replicates, were completely covered in water-based medium-expansion foam for a 15-min dwell time in a bulk container. Container fill time for the trials were 6.5 ± 0.68 s and 5.3 ± 0.03 s for finisher and suckling pig replicates, respectively. Average (± SD) time for cessation of movement was 105 ± 39.1 s (s) for finisher pigs and 79.5 ± 10.5 s for suckling pigs. After completion of the 15-min dwell time in the foam, all pigs were confirmed dead upon removal from the container. The results from the present study suggest that the use of water-based foam can be an effective means of mass depopulation for suckling and finisher stage pigs, supporting previous research on the application to adult swine.