Abstract

The study was conducted in six districts of Sidama Zone, Southern Ethiopia. During the study a total of 1627 indigenous zebu cattle in 124 herds were considered from extensive management system. Serum samples collected were screened using Rose Bengal plate test (RBPT) and positive reactors were further subjected to complement fixation test to maximize specifity and positive predictive value. In the study, an over all prevalence of 1.66% has been established and the herd level infection rate was 13.70 % (n = 124). Infected herds have been detected from all districts except Arroresa.  Accordingly, the rate of seroreactor herds observed were, 33.3% (n = 6) for Awassa, 15.38% (n = 26) for Yirgalem, 13.15% (n = 38) for Aletawendo, 14.29% (n = 14) for Hagereselam and 18.18% (n = 22) for Arbegona in extensive management. Regarding herd size, 4.81% for small, 50% for medium and 70% infection rate was recorded for large herds. The variation between small and large herd size was statistically significant (P < 0.01). In general the study concluded that brucellosis is prevalent at low rate in individual level, while relatively high in herd level and wide in geographic distribution. 

Key words: Brucellosis, complement fixation test, extensive management system,   prevalence, Rose Bengal plate test, Zebu cattle.