Table 3.
Effect of litter size, mean piglet BW at birth (BWB), time from last meal until the onset of farrowing (TMLUOF), and absence/presence of farrowing assistance (FA) on birth intervals, the need for farrowing assistance, and the incidence of stillbirth
| Item | Birth intervals | Odds ratio of farrowing assistance1 | Odds ratio of stillbirth | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Estimate | SEM | P-value | Estimate | LCL | UCL | P-value | Estimate | LCL | UCL | P-value | |
| Intercept | 4.06 | 7.42 | 0.59 | ||||||||
| Litter size | −0.29 | 0.22 | 0.18 | 1.00 | 0.92 | 1.09 | 0.94 | 1.01 | 0.96 | 1.07 | 0.63 |
| BWB | 11.5 | 3.61 | 0.002 | 0.60 | 0.13 | 2.73 | 0.51 | 0.25 | 0.10 | 0.65 | 0.005 |
| TMLUOF2 | |||||||||||
| ≤3 h (Ref) | 0.00 | 1.00 | 1.00 | ||||||||
| 3 to 6 h | 6.37 | 1.53 | < 0.001 | 5.27 | 1.56 | 17.8 | 0.008 | 1.11 | 0.69 | 1.77 | 0.67 |
| > 6 h | 15.7 | 1.75 | < 0.001 | 9.17 | 2.71 | 31.1 | < 0.001 | 1.76 | 1.09 | 2.86 | 0.02 |
| FA | |||||||||||
| No (Ref) | 0.00 | 1.00 | |||||||||
| Yes | 3.62 | 1.49 | 0.02 | 1.46 | 1.03 | 2.08 | 0.03 | ||||
1LCL = lower confidence limit; UCL = upper confidence limit.
2TLMUOF was categorized into 3 classes based on the observed break point for the farrowing length; Ref. is the reference value for comparison with the rest of the classes.