TABLE 3.
Variables associated with serological results in the logistic regression modela
| Variable | Model 1
|
Model 2
|
||
|---|---|---|---|---|
| Coefficient (P) | OR (95% CI) | Coefficient (P) | OR (95% CI) | |
| Constant | 0.57 (0.386) | 0.05 (0.916) | ||
| Feeding of silage | 1.87 (<0.001) | 6.51 (2.38-17.80) | 1.70 (<0.001) | 5.48 (2.12-14.17) |
| Brown Swiss breed | −1.29 (0.005) | 0.28 (0.11-0.69) | −1.32 (0.005) | 0.27 (0.11-0.66) |
| Rubber mat | −1.59 (0.024) | 0.20 (0.05-0.81) | ||
| Cow trainer | −1.03 (0.040) | 0.36 (0.13-0.95) | ||
a
Model 1, 75% of outcomes correctly predicted, the chi-square for likelihood ratio test of 27.34 (P < 0.001); model 2, 72% of outcomes correctly predicted, chi-square for likelihood ratio test of 25.96 (P < 0.001).