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

Treatment structure was arranged as a 2 × 4 × 7 factorial with two feed matrices (complete diet [FEED] and SDPP) and chemical treatment factors including no addition of feed additives, addition of a BA product (0.5%; DSM Nutritional Products Inc., Parsippany, NJ), addition of an EO product (EO; 0.02%; DSM Nutritional Products Inc., Parsippany, NJ), and combination of both products (0.5% BA and 0.02% EO). Owing to the laboratory analysis procedures requiring separate experimental units to be analyzed on each day, the final factor in the factorial arrangement was day of analysis (d 0, 1, 3, 7, 14, 21, and 42 qRT-PCR before initiation of the experiment. SDPP (APC Functional Proteins, Ankeny, IA) was also verified by qRT-PCR to be free of both PEDV and PDCoV RNA before use.