Table 5 Calving number and percentage of stillbirths for variables included in the binary logistic regression model of the generalized linear mixed model for cow-level risk factors for stillbirth incidence in Holstein dairy cows (n = 51,405).
Variable | Calving No | Stillbirth% | P-value |
|---|---|---|---|
Calving year | < 0.01 | ||
2011 | 6236 | 4.63 | |
2012 | 6775 | 5.28 | |
2013 | 6925 | 5.09 | |
2014 | 8215 | 4.35 | |
2015 | 8615 | 4.36 | |
2016 | 9640 | 3.20 | |
2017 | 4999 | 3.42 | |
Calving season | |||
Spring | 11,114 | 4.20 | < 0.01 |
Summer | 15,687 | 4.89 | |
Autumn | 13,498 | 4.26 | |
Winter | 11,106 | 3.57 | |
Calving season × Twin status | < 0.01 | ||
Calving season × Calf birth weight | < 0.01 | ||
Parity | < 0.01 | ||
1 | 31,093 | 3.34 | |
2 | 8944 | 5.75 | |
3 | 5378 | 5.93 | |
4 ≤ | 5990 | 5.34 | |
Parity × Twin status | < 0.01 | ||
Twin status | < 0.01 | ||
Single birth | 49,591 | 2.00 | |
Twin birth | 1814 | 6.70 | |
Dry period length | 0.08 | ||
< 45 days | 26,416 | 4.10 | |
46–60 days | 16,056 | 4.44 | |
61–100 days | 5957 | 4.44 | |
> 100 days | 2976 | 5.30 | |
Dry period length × Twin status | < 0.01 | ||
Gestation length | < 0.01 | ||
Calf birth weight | < 0.01 | ||
≤ 35 | 6806 | 9.63 | |
35.1–38 | 8424 | 4.99 | |
38.1–40 | 8335 | 2.61 | |
40.1–42 | 7092 | 2.50 | |
42.1–44 | 7085 | 2.83 | |
44.1–46 | 4960 | 2.70 | |
46 < | 8703 | 3.87 | |
Calf sex | 0.02 | ||
Female | 25,504 | 4.12 | |
Male | 25,901 | 4.49 | |
Dystocia | < 0.01 | ||
No | 43,810 | 3.44 | |
Yes | 7595 | 9.26 |
