Table 2.
Detection of bovine respiratory syncytial virus (BRSV) by virus isolation and qPCR for the BRSV NS2 gene in nasal swabs and lungs after BRSV-PM coinfection of calves supplemented with or without SCFP for 32 d
| Nasal swabs | Lung1 | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Day 0 | Day 2 | Day 4 | Day 6 | Day 8 | Day 10 | SEM | Day 9 or 10 | SEM | ||
| Control | Virus isolation | 0/13 | 0/13 | 4/13 | 13/13 | 4/13 | 1/12 | 4/13 | ||
| NS gene copies/104 RPS9 copies2 | ND3 | ND | 25,800 | 2,313,000 | 21,400 | 384 | 2,120,000 | 307 | 306 | |
| SCFP4 | Virus isolation | 0/13 | 0/13 | 3/13 | 12/13 | 3/13 | 1/13 | 3/13 | ||
| NS gene copies/104 RPS9 copies | ND | ND | 3,490 | 4,480 | 715 | 549 | 3,450 | 32 | 32 |
1These data include the results from the calf in the control group that was euthanized on day 8 post-infection for humane reasons. The lung tissue from this animal was positive for BRSV.
2Nasal swabs: treatment effect P = 0.33; time effect P = 0.43; treatment × time interaction P = 0.44. Lung tissue: treatment effect P = 0.48.
3ND, not detected.
4SCFP, calves fed S. cerevisiae fermentation products, 1 g/d SmartCare suspended in milk and 5 g/d NutriTek on calf starter.