Table 3.

Results of the multivariable logistic regression model showing significant risk factors for perinatal calf mortality

Variable	Level	Estimate	se	OR (95% CI)	P value
Intercept		−4.28	1.08		<0.001
Herd*	A	Reference
	B	−0.0885	1.27	9.2 (0.0072–0.076)	0.94
	C	0.477	1.19	1.6 (0.080–20)	0.69
	D	0.391	1.20	1.5 (0.17–31)	0.75
	E	19.5	1289	2.9†	0.99
	F	0.723	1.16	2.1 (0.27–42)	0.53
	G	0.847	1.27	2.3 (0.21–52)	0.50
	H	20.1	936	5.2†	0.98
	I	1.38	1.11	4.0 (0.62–77)	0.21
	J	1.10	1.10	3.0 (0.49–57)	0.32
	K	2.28	1.07	9.4 (1.8–183)	0.03
Calf sex	Female	Reference
	Male	0.909	0.353	2.5 (1.3–5.1)	0.01
Plurality	Single	Reference
	Twin	1.25	0.427	3.5 (1.5–8.0)	0.003
Level of calving assistance	Unobserved	Reference
	Observed, unassisted	−1.78	0.501	0.17 (0.058–0.42)	<0.001
	Mild assistance	−0.325	0.510	0.72 (0.25–1.9)	0.52
	Hard assistance, vet assistance or caesarean	1.17	0.438	3.2 (1.4–7.7)	0.007

*Herd was included to control for unmeasured or unobserved differences among herds.

†Too few observations were collected for practical calculation of this confidence interval (CI).