Bovine mastitis and its associated risk factors in lactating cows in Wolayta Soddo, southern Ethiopia
A cross-sectional study of bovine mastitis was conducted on 275 lactating cows from November 2007 to April 2008 to estimate the prevalence of mastitis and to determine the pathogens causing mastitis with the associated risk factors. Diagnosis was based on clinical examination of the udder and milk and the use of White Side Test (WST) as a screening test for subclinical mastitis. The overall prevalence of bovine mastitis was 27.3% with clinical and subclinical mastitis contributing 9.5 % and 23.4 %, respectively. Significant (P<0.05) differences in mastitis prevalence were observed between cows in different lactation stages and ages, breeds, animals with teat lesion, tick infestation and previous exposure to mastitis. Animals having udder and/or teat injury were affected at higher rate (OR=2.5, P< 0.05) than those without injury. Cows with tick infestation on skin of udder and/or teats were affected at higher rate (OR=3.3, P < 0.05) as compared to animals without tick infestation. Microbiological examination of milk samples from affected cows revealed different genera including Staphylococci (66.7%), Streptococci (47.4%), Micrococci (11.6%), Coliform (2.9%) and Corynebacterium (1.5 %). The prevalence of bovine mastitis in the study area was sufficiently high as to cause substantial economic loss to farmers. It is, therefore, imperative that measures aimed at prevention and control of mastitis should be instituted in the area.
Keywords: Bovine mastitis, White Side Test, risk factors, Wolayta Soddo, Ethiopia.