Longitudinal study of calf morbidity and mortality and the associated risk factors on urban and peri-urban dairy farms in southern Ethiopia

Table 6 Risk factors for calf mortality rate based on multivariable Cox regression analysis

Variables	Category	HR	P >z	95% CI for HR
Age of calves	< 3 mon	Ref
Age of calves	>3 mon	0.14	0.002	0.04 - 0.48
Calving difficulty	No	Ref
Calving difficulty	Yes	9.3	<0.001	3.08 - 28.02
Time of separation of calves from dams	Immediately after birth	Ref
Time of separation of calves from dams	After sucking colostrum	0.40	0.028	0.18 - 0.90
Farmer’s education	No formal Edu	Ref
	Primary	0.28	0.061	0.07 - 1.06
	Secondary	0.08	0.019	0.01 - 0.65
	College	0.13	0.001	0.04 - 0.41

ISSN: 1746-6148