An all-in-one concept of a mobile system for on-farm swine depopulation, pathogen inactivation, off-site carcass disposal, and biosecure cleanup

Authors: LEE, MYEONGSEONG - Texas A&M University; Koziel, Jacek; RAMIREZ, BRETT - Iowa State University; CHEN, BAITONG - South Coast Air Quality Management District; LI, YUZHI - University Of Minnesota

Submitted to: AgriEngineering
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/9/2022
Publication Date: 12/13/2022
Citation: Lee, M., Koziel, J.A., Ramirez, B.C., Chen, B., Li, Y. 2022. An all-in-one concept of a mobile system for on-farm swine depopulation, pathogen inactivation, off-site carcass disposal, and biosecure cleanup. AgriEngineering. 4(4):1184-1199. https://doi.org/10.3390/agriengineering4040074.
DOI: https://doi.org/10.3390/agriengineering4040074

Interpretive Summary: A highly infectious disease outbreak challenges the livestock production system and forces difficult decisions to depopulate entire herds. Depopulation generates carcasses that could still be infectious. Scientists from ARS (Bushland, Texas), Iowa State University, Texas A&M University, and University of Minnesota developed an 'all-in-one' concept of a mobile, trailer-based system for on-farm swine depopulation, pathogen inactivation, off-site carcass disposal, and biosecure cleanup. The concept uses vaporized CO2 followed by heat treatment. A user-friendly model for estimating a wide range of site- and scenario-specific CO2 amounts and times required to inactivate targeted swine pathogens was developed. The model illustrates the depopulation of a swine herd for two diseases of concern, African swine fever (ASF) and the porcine reproductive and respiratory syndrome (PRRS) viruses. For example, as many as 7 batches of 24 pigs 220 lbs each could be euthanized with a 150 lbs standard liquid CO2 cylinder in a modified 16 x 7 x 4 ft trailer. The time required for complete inactivation of ASF and PRRSV inside carcass for one batch was estimated to be 4.5 h and 3.3 h, respectively, assuming well-insulated trailer, 650,000 BTU/h direct fired heaters with setpoint trailer temperature at 212 deg F and 33 deg F ambient temperature. The proposed ‘all-in-one’ trailer concept could be adopted for a routine (single mobile unit) or a mass depopulation (fleet of mobile units) scenarios.

Technical Abstract: Infectious animal diseases can cause severe mortality on infected farms. An outbreak challenges the system and forces difficult decisions to stop the disease progression. We propose an 'all-in-one' concept of a mobile system for on-farm swine depopulation and pathogen inactivation. The system uses vaporized CO2 followed by heat treatment, broadening options for off-site carcass disposal and cleanup. A direct-fired heater supplies heat into the insulated trailer to reach and maintain the inactivation temperature for targeted pathogens. We developed a user-friendly model based on engineering principles for estimating site- and scenario-specific CO2 amounts and times required to inactivate targeted pathogens. Multipoint CO2 injection and improved distribution to animals follow the plug-flow reactor air replacement model. The model illustrates the depopulation and inactivation of two diseases, African swine fever (ASF) and the porcine reproductive and respiratory syndrome (PRRS) viruses. The model allows for dump trailer size, pig number, weights, and environmental conditions input. Model outputs provide users with practical information about the required CO2 injection rate, temperature setpoints, and times to effectively depopulate and inactivate pathogens in carcasses. The concept could be adopted for a routine or a mass depopulation/treatment/disposal with a single or fleet of 'all-in-one' units.