Table 4.
Results of multivariate analysis of risk factors for stillbirth (995 piglets).
| Stillbirth | OR; 95%CI | Nagelkerke R2 change | p-value |
|---|---|---|---|
| BO | 1.21; 1.14-1.28 | 0.0834 | <0.001 |
| PI | 0.96; 0.94-0.98 | 0.1176 | <0.001 |
| BI | 1.01; 1.00-1.01 | 0.1476 | <0.001 |
| GL=114-116 days | 1 | 0.1660 | |
| GL=117-119 days | 2.12; 1.10-4.08 | 0.024 | |
| GL=112-113 days | 5.50; 2.50-12.07 | <0.001 | |
| Parity=6-10 | 1 | 0.2153 | |
| Parity=2 | 0.03; 0.004-0.26 | 0.001 | |
| Parity=1 | 0.32; 0.12-0.84 | 0.021 | |
| Parity=3-5 | 0.46; 0.27-0.78 | 0.004 |
OR=Odds ratio, CI=Confident interval, p=Probability level, BO=Birth order, PI=Ponderal index, BI=Birth interval, GL=Gestation length. The final model selected BO, PI, BI, GL, and parity as the five most significant factors for stillbirth in piglets. The overall significance of final model was 0.001. The final model explained 21.53% variation of the stillbirth. The Hosmer-Lemeshow goodness of fit test showed a good fit between expected and predicted outcome (p=0.778)