Prevalence of Bovine Mastitis and Assessment of Risk Factors in and Around Wolayta Sodo, Ethiopia

A cross sectional study was conducted in and around Woliata Soddo in different dairy breeds (jersey, indigenous zebu, and high grade Holstein breed) from November 2013 to May 2014 to estimate the prevalence of mastitis and to assess the associated risk factors at Soddo regional veterinary laboratory. A total of 386 lactating cows of which 216 indigenous zebu, 88 jersey, 82 high grade Holsteins underwent a clinical examination and Californian Mastitis Test (CMT) was performed. Moreover, those positive for the clinical and sub clinical mastitis were subjected to bacteriological tests. N. 134 (34.7%) were found to be positive for either clinical (38.80%) or subclinical mastitis (61.19%). Of the 966 quarters examined, 21.94% were found positive to mastitis. The prevalence of mastitis differed significantly among the breeds (P< 0.000) with 54.8% in high grade Holstein cows, 44.3% in jersey cows and 23.1% in indigenous zebus. However, there was no significant difference among breeds as to quarters. With respect to lactation stage, the prevalence of mastitis was 43.85% at early lactation (1-120 days), 32.80% at mid lactation (121-240 days), and 23.8% at end lactation (above 240 days). Moreover, there was a significant difference between lactation (P< 0.000). The prevalence of mastitis in various group was found to be increasing with parity number (r= 0.8) with highest prevalence at lactation stage number six and above. Of the total 134 CMT positive and clinically positive udder quarter sample analyzed microbiologically, 111 (82.8%) were culturally positive and 23 (17.2%) were negative. In positive samples, Staphylococcus accounts for 43.54%, Streptococcus 28.89%, Coliform 19.35% respectively, of the total 124 bacteria isolated. Based on the result obtained, recommendations were forwarded to build up awareness among dairy cow owners and further investigation with special emphasis on economic losses.