CategorySwine Health - General Disease
Date Full Report Received12/29/2016
Date Abstract Report Received12/29/2016
Funded ByNebraska Pork Producers Association
This project was conducted in an effort to determine the transmission risk for PEDv following on-farm composting of PEDv-positive swine mortalities. The studies performed were designed to quantify the persistence of PEDV RNA via quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) at various time-temperature combinations and in infected piglet carcasses subjected to composting.
Specific objectives of this project were to:
1.) Identify appropriate time-temperature combinations for inactivation of PEDv in compost material.
2.) Validate time-temperature combinations for PEDv inactivation in mortality compost piles.
3.) Increase confidence among pork producers and their advisors in utilizing on-farm composting as a biosecure method for disposing of PEDv-infected animals.
Identification of Time-Temperature Combinations for PEDv Inactivation (Obj. 1)
This study was conducted to quantify the persistence of PEDv RNA via quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) at various time-temperature combinations under controlled laboratory conditions.
Porcine Epidemic Diarrhea Virus was inoculated into cell culture media at 1 x 105 TCID50 per sample (1 mL sample size) at various time and temperature combinations including temperatures of 37, 45, 50, 55, 60, 65, 70°C and exposure times of 0, 24, 48, 72, 96, 120, 168 and 336 hrs. The temperature treatments were performed in incubators (Heratherm General Protocol Incubator, Thermo Fisher Scientific, Waltham, MA) maintained at the target temperatures, which were monitored for consistency throughout the trial. At each designated time point in the experiment, three cryovials were removed from the incubator and transferred to -80°C for storage until analysis by qRT-PCR. At all temperatures, virus RNA copies declined over time and with the decline most marked and rapid for temperatures of 65 and 70°C. Two of three samples had undetectable virus RNA after 336 hrs incubation at 70 °C.
Impact of Composting on Inactivation of PEDv (Obj. 2)
This study was conducted to quantify the persistence of PEDv RNA via quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) following composting of PEDV-positive piglets.
Producer Outreach (Obj. 3)