A cross sectional study to determine the prevalence of bovine mastitis in Jersey, Indigenous and Holstein Friesian was carried out from November 2011 to April 2012 in and around Wolaita Sodo town. This study based its operation center at Sodo Regional Laboratory, department of bacteriology.

A total of 349 dairy milking cows were studied 62 Jersey, 237 Indigenous Zebu and 50 Holstein by using California Mastitis Test (CMT). Prevalence of bovine mastitis at cow level was 35.5% (124/349), out of which 5.4% (19/349) and 30.1%) 105/349) were clinical and sub clinical, respectively. The quarter level prevalence was 25.7% (359/1396); from this the clinical and sub clinical forms were 4.4% (62/1396) and 21.3% (297/1396), respectively. The prevalence of blind quarter in the current study was 3.8% (53/1396) while the active clinical form of quarter was 4.4 %( 62/1396). Samples from all 62 active clinical cases and 96.6% (287/297) of the California Mastitis Taste (CMT) - positive sub clinical quarters were found to be culture positive. From CMT - positive sub clinical quarters, 3.4% (10/297) were found to be culture negative. From 349 culture positive samples, a total of 113 bacteria were isolated, the most prevalent being S. aurues (53.9%). Other bacterial isolates included Streptococcus species (39.8%), E. coli (2.7%), and Corynebacterium species (1.8%) and Salmonella (1.8%). Risk factors analysis revealed that the prevalence significantly differed with parity (p< 0.05) and insignificantly differed with the other risk factors. This study revealed high prevalence of mastitis thus based on this some recommendations was forwarded aiming at reducing the prevalence of the disease.