Table 5 Estimates from the multivariable logistic model of having twins versus singleton as dependent variable
From: Risk factors associated with cystic ovarian disease in Norwegian dairy cattle
Variable | Class | N | Estimate (stderr) | OR (95% CI) |
|---|---|---|---|---|
Intercept | 156,661 | -3.39 (0.04) | ||
Parity | 1 | 63,038 | 0.00 | 1.0 |
2 | 44,182 | 0.20 (0.04) | 1.2 (1.1 - 1.3) | |
> 2 | 49,441 | 0.32 (0.03) | 1.4 (1.3 - 1.5) | |
Diagnosis of COD during lactation | No | 155,455 | 0.00 | 1.0 |
Yes | 1,206 | 0.77 (0.11) | 2.2 (1.7 - 2.7) | |
Lactation start with | Singleton | 147,096 | 0.00 | 1.0 |
Twins | 2902 | 1.09 (0.07) | 3.0 (2.6 - 3.4) | |
Triplets | 7 | 1.46 (1.12) | 4.3 (0.5 - 39) | |
Others* | 6,656 | 0.05 (0.07) | 1.1 (0.9 - 1.2) | |
Calving season | March-May (spring) | 37,141 | 0.00 | 1.0 |
September-November (autumn) | 49,171 | - 0.14 (0.04) | 0.9 (0.8 - 0.9) | |
December-February (winter) | 30,545 | - 0.08 (0.04) | 0.9 (0.8 - 1.0) | |
June-August (summer) | 39,804 | 0.06 (0.04) | 1.1 (1.0 - 1.2) | |
Region | < 60° latitude | 39,175 | 0.00 | 1.0 |
60 to 65 ° | 102,066 | - 0.20 (0.03) | 0.8 (0.8 - 0.9) | |
> 65 ° | 15,420 | - 0.27 (0.06) | 0.8 (0.7 - 0.9) | |
Herd effect | 13,080 | 0.06 (0.03) | 1.1 (1.0 - 1.1) |