Table 2.
Percentage of calves from each pen cohort from which M. haemolytica, P. multocida, and H. somni were recovered at 1DOF (n = 799 calves) at on-arrival processing and before metaphylaxis, 13DOF (n = 798), and 36DOF (n = 80) for the 2020 study population.
| Metaphylaxis Drug | Pen | Sampling Time | No. Calves | Recovery Rates of BRD Pathogens from Calves | ||
|---|---|---|---|---|---|---|
| M. haemolytica | P. multocida | H. somni | ||||
| tulathromycin | 1 | 1DOF | 100 | 26% | 32% | 4% |
| 13DOF | 100 | 77% | 2% | 0% | ||
| 36DOF | 10 | 80% | 20% | 30% | ||
| tulathromycin | 2 | 1DOF | 100 | 35% | 47% | 3% |
| 13DOF | 100 | 84% | 7% | 1% | ||
| 36DOF | 10 | 70% | 10% | 50% | ||
| tulathromycin | 3 | 1DOF | 100 | 47% | 48% | 6% |
| 13DOF | 100 | 70% | 13% | 0% | ||
| 36DOF | 10 | 80% | 40% | 30% | ||
| tulathromycin | 4 | 1DOF | 100 | 47% | 55% | 4% |
| 13DOF | 100 | 80% | 21% | 4% | ||
| 36DOF | 10 | 80% | 20% | 60% | ||
| tulathromycin | 5 | 1DOF | 100 | 33% | 67% | 12% |
| 13DOF | 100 | 14% | 11% | 2% | ||
| 36DOF | 10 | 80% | 10% | 40% | ||
| tulathromycin | 6 | 1DOF | 99 | 33% | 63% | 7% |
| 13DOF | 99 | 9% | 8% | 5% | ||
| 36DOF | 10 | 70% | 20% | 30% | ||
| tulathromycin | 7 | 1DOF | 100 | 28% | 70% | 12% |
| 13DOF | 99 | 30% | 11% | 12% | ||
| 36DOF | 10 | 70% | 30% | 100% | ||
| tulathromycin | 8 | 1DOF | 100 | 15% | 70% | 29% |
| 13DOF | 100 | 57% | 8% | 11% | ||
| 36DOF | 10 | 70% | 20% | 50% | ||