Epidemiological studies on subclinical mastitis in dairy goats in northern regions of Bangladesh

A cross sectional study was carried out from June, 2008 to December, 2010 to estimate the prevalence of subclinical mastitis and to determine the responsible bacterial pathogens in lactating dairy goats in northern districts of Bangladesh. A total of 292 goats and 584 udder halves milk samples were screened using California Mastitis Test (CMT). Prevalence of subclinical mastitis at goat level was 56.2% (164/292), and in udder half level it was 33.9% (198/584). The subclinical mastitis prevalence at goat level was high (71.6%) in Jamnapari goats as compared to Black Bengal goats (50.2%), whereas at the udder half level, subclinical mastitis prevalence was 45.1% and 29.6% in Jamnapari and Black Bengal goats, respectively. The pathogens isolated from subclinical mastitic milk samples were coagulase negative Staphylococci , Coliforms, Streptococcus spp. , Staphylococcus aureus , Micrococcus spp., Pseudomonas aeruginosa and Bacillus cereus. Among these, the most frequent isolates were coagulase negative Staphylococci (28.8%), Coliforms (22.7%) and Streptococcus spp (15.2%). Out of four potential host related risk factors considered, litter size and body condition of goats were found to influence the prevalence rate of subclinical mastitis in goat significantly ( p< 0.05 ). On the other hand, the subclinical mastitis was very significantly ( p=0.0001 ) associated with the housing system of goats, i.e., goats reared in raised floor had a low subclinical mastitis infection rate (35.8%) as compared to reared in earth floor (62.2%). Antibiogram studies were also performed for the bacterial isolates and Gentamicin was found to be the most effective drug. Bangladesh J. of Livestock Res. 19(1-2): 112-122, Jan-Dec 2012