Table 7.
Significant results obtained from logistic regression of antimicrobial resistant Mannheimia haemolytica from dairy-type cattle upon feedlot arrival.
| Risk factor | Ampicillin | Danofloxacin | Florfenicol | Oxytetracycline | Penicillin | Tilmicosin | Tulathromycin | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| OR | 95% CI | p-value | OR | 95% CI | p-value | OR | 95% CI | p-value | OR | 95% CI | p-value | OR | 95% CI | p-value | OR | 95% CI | p-value | OR | 95% CI | p-value | |
| Country | |||||||||||||||||||||
| CA | 1 | 1 | – | 1 | 1 | – | 1 | 1 | – | 1 | 1 | – | 1 | 1 | – | 1 | 1 | – | 1 | 1 | – |
| US | na | na | na | 0.02 | 0.002–0.2 | 0.001 | 18.7 | 3.3–251.8 | 0.004 | na | na | na | na | na | na | na | na | na | na | na | na |
| Monthly intervals | |||||||||||||||||||||
| Aug–Nov | 1 | 1 | – | 1 | 1 | – | 1 | 1 | – | 1 | 1 | – | 1 | 1 | – | 1 | 1 | – | 1 | 1 | – |
| Dec–Feb | 1.0 | 0.2–6.0 | 0.964 | 8.1 | 1.3–50.7 | 0.025 | 9.5 | 1.6–68.3 | 0.017 | 3.33 | 0.9–13.0 | 0.082 | 0.9 | 0.2–3.3 | 0.831 | 3.3 | 0.9–12.4 | 0.077 | 0.3 | 0.02–4.7 | 0.426 |
| Mar–May | 0.2 | 0.03–1.1 | 0.057 | 1.1 | 0.3–3.5 | 0.900 | 1.9 | 0.4–10.8 | 0.465 | 0.95 | 0.3–2.8 | 0.930 | 0.2 | 0.03–0.9 | 0.031 | 0.2 | 0.05–0.9 | 0.041 | 0.1 | 0.01–0.9 | 0.049 |
| Mannheimia haemolytica serotype | |||||||||||||||||||||
| A2 | 1 | 1 | – | 1 | 1 | – | 1 | 1 | – | 1 | 1 | – | 1 | 1 | – | 1 | 1 | – | 1 | 1 | – |
| A1 + A6 | 0.5 | 0.1–1.8 | 0.259 | 12.1 | 3.4–43.3 | <0.001 | 0.02 | 0.002–0.1 | <0.001 | 4.8 | 1.9–11.9 | <0.001 | 0.1 | 0.01–0.4 | 0.004 | 0.1 | 0.05–0.4 | <0.001 | 0.03 | 0.01–0.2 | <0.001 |
CA, Canada; CI, confident interval; OR, odds ratio; RF, risk factor.
na, that variable was not significant at the p-value ≤ 0.1 level and was eliminated from the regression.
Bold p-values indicate statistically significant results at p ≤ 0.1.