STUDIES ON PREVALENCE, ETIOLOGY AND DIAGNOSIS OF SUBCLINICAL MASTITIS AMONG CROSSBRED COWS

Incidence of subclincial mastitis (SCM) among crossbred cattle from organized dairy farmswas studied. The quarter-wise and animal-wise incidence of SCM was 15.62 and 43.33 percent, respectively. Maximum number of animals (74.36 %) were having one quarter infection.Right-hind quarters were having higher incidence (38.18%) compared with other quarters. Theincidence of SCM was lowest during first lactation which increased with subsequent lactationsand was highest in sixth and above lactations. Bacteriological isolations revealed that Staphylococcus aureus was the major pathogen (56.89%) followed by Micrococcus spp.(15.51 %) Bacillus spp. (12.06 %) , Staphylococcus epidermidis (8.62 %), Klebsiella spp (3.44 %), E. coli (1.72 %) and Corynebacterium spp. (1.72 %). Among the indirect tests, SLS was found to be highly (19.03 %) effective in detection of subclinical mastitis followed by WST, BTB Card test and CMT (15.90, 15.62 and 14.77 %, respectively). The percentage of agreement of CMT, SLS, BTBCard test and WST with bacteriological examination were found to be 57.89, 62.07, 64.46 and68.65 per cent, respectively.