author(s)
Srijit Tripathi, Niddhi Arora, S Shekhar and VS Rajora

abstract
The aim of the present investigation was to assess the efficacy of California mastitis test (CMT) to detect sub clinical mastitis (SCM) and to study its etio-prevalence in crossbred cattle. In the present study, out of 112 crossbred cows studied, 63 were positive for subclinical mastitis. Among a total of 428 quarters, 142 quarters were found positive for subclinical mastitis. The overall and quarter wise prevalence of subclinical mastitis was computed to be 56.25% and 33.17% respectively. Staphylococcus sp. (66.90%) Streptococcus sp. (23.23%) and Escherichia coli (2.81%) were the most prevalent bacterial agents. Quarter wise highest (31.57%) infection of Staphylococcus spp. was observed in right hind quarter followed by left hind quarters (29.47%), right fore quarters (20.00%) and left fore quarters (18.94%). Quarter wise highest (31.57%) infection of Staphylococcus spp. was observed in right hind quarter followed by left hind quarters (29.47%), right fore quarters (20.00%) and left fore quarters (18.94%). Streptococcus spp. infection was found maximum (36.36%) in left hind quarter followed by right hind quarters (33.33%), and left fore quarters (18.18%) and right fore quarters (12.12%). Two cases (50%) of E. coli were seen in right hind quarter while one case each was seen in both left hind and right front quarter. Mixed infection was recorded greatest (40.00%) in left hind quarter.