Table 5.

Association between animal characteristics and seropositivity of Brucella assessed by logistic regression and Chi-square

Factors	Level	n	Test +ve	%	OR	95 % CI	Z-test	P value
Age	0.5 ≤ 3a	233	1	0.4
	3 ≤ 6	308	4	1.3	3.2262	28.32–30.53	1.0386	0.299
	≥7	263	14	5.3	11.376	90.33–85.47	2.3308	0.0198
Sex	Fa	529	18	3.4
	M	275	1	0.4	0.104	0.014–0.78	−2.3742	0.007
Breed	Arsia	494	16	3.2
	HF	149	1	0.7	0.1724	0.302–3.75	−1.3915	0.1641
	Boran	161	2	1.2	0.4001	2.02–4.15	−0.8571	0.3914
Herd size	≤20a	232	6	2.3
	>20	572	13	2.6	1.6378	4.30–5.28	0.3586	0.7199

^aOthers were computed in reference to this category