Determining the impact of commercial feed additives as potential porcine epidemic diarrhea virus mitigation strategies as determined by polymerase chain reaction analysis and bioassay()

Gebhardt, Jordan T; Woodworth, Jason C; Jones, Cassandra K; Tokach, Mike D; Gauger, Philip C; Main, Rodger G; Zhang, Jianqiang; Chen, Qi; DeRouchey, Joel M; Goodband, Robert D; Stark, Charles R; Bergstrom, Jon R; Bai, Jianfa; Dritz, Steve S

Separate bottles were analyzed on d 0, 1, 3, 7, 14, 21, and 42 post-laboratory inoculation. On each day of analysis, 100 mL phosphate-buffered saline (PBS; pH 7.4 1×, Life Technologies, Grand Island, NY) was added to each bottle predetermined for analysis on that day. Bottles were shaken for approximately 10 s, at which point they were allowed to settle overnight at 4 °C. The following day, supernatant was pulled and aliquoted for further analysis. A total of four aliquots from each sample bottle were collected and stored at −20 °C until the conclusion of the trial, at which point qRT-PCR analysis was performed on one aliquot per sample bottle and the remaining three samples per bottle were stored at −80 °C until transported to Iowa State University for the initiation of the bioassay portion of the experiment.