Table 1.
Summary of experimental design of bovine coronavirus (BoCV) and bovine viral diarrhea virus (BVDV) dual infections.
| Study 1 | ||||||
|---|---|---|---|---|---|---|
| Study purpose | Single infection. Comparison of BoCV strains. Determine if variation exists among BoCV strains and select BoCV strain from subsequent studies. |
|||||
| Groups | Control (n = 2) | 1A (n = 3) | 1B (n = 3) | 1C (n = 3) | 1D (n = 3) | 1E (n = 3) |
| Treatment | No virus | OK 1776* | OK An5* | OK 43* | OK 834* | NVSL† |
| Experimental design | All inoculations occurred on day 0 | |||||
| Study 2 | ||||||
| Study purpose | Dual infection. Determine outcome of sequential infections when second virus exposure occurs 3 d after first virus exposure. Viruses used: BoCV strain OK 1776, BVDV-2a strain RS886‡. |
|||||
| Groups | 2A (n = 2) | 2B (n = 3) | 2C (n = 3) | 2D (n = 2) | ||
| Treatment | Only BoCV | BoCV followed 3 d later by BVDV-2a | BVDV-2a followed 3 d later by BoCV | No virus control | ||
| Experimental design | day 0 | BoCV | BoCV | BVDV-2a | No virus | |
| day 3 | No virus | BVDV-2a | BoCV | No virus | ||
| Study 3 | ||||||
| Study purpose | Dual infection. Determine outcome of sequential infections when BVDV exposure occurs first followed by BoCV exposures at 6 or 9 d after BVDV exposure. Viruses used: BoCV strain OK 1776; BVDV-2a strain RS886. |
|||||
| Groups | 3E (n = 3) | 3F (n = 3) | 3G (n = 3) | 3H (n = 2) | ||
| Treatment | BVDV-2a followed 9 d later by BoCV | BVDV-2a followed 6 d later by BoCV | Only BVDV-2a | No virus control | ||
| Experimental design | day 0 | BVDV-2a | No virus | No virus | No virus | |
| day 3 | No virus | BVDV-2a | No virus | No virus | ||
| day 7 | No virus | No virus | BVDV-2a | No virus | ||
| day 9 | BoCV | BoCV | No virus | No virus | ||
| Study 4 | ||||||
| Study purpose | Dual infection. Determine outcome of sequential infections when BVDV exposure occurs first followed by BoCV exposures at 6 or 9 d after BVDV exposure. Viruses used: BoCV strain OK 1776; BVDV-2a strain RS886. |
|||||
| Groups | 4M (n = 4) | 4N (n = 4) | 4O (n = 2) | 4P (n = 2) | 4Q (n = 2) | |
| Treatment | BVDV-2a followed 9 d later by BoCV | BVDV-2a followed 6 d later by BoCV | BVDV-2a only | No virus control | BoCV only | |
| Experimental design | day 0 | BVDV-2a | No virus | BVDV-2a | No virus | No virus |
| day 3 | No virus | BVDV-2a | No virus | No virus | No virus | |
| day 9 | BoCV | BoCV | No virus | No virus | BoCV | |
*
Field isolate of BoCV provided by Oklahoma State University (Stillwater, OK).
†
Reference strain of BoCV provided by National Veterinary Services Laboratories (Ames, IA).
‡
Field isolate of BVDV-2a provided by National Animal Disease Center (Ames, IA).