Comparison of das-elisa with other conventional tests for diagnosis of staphylococcal subclinical mastitis in cows

Double Antibodies Sandwich ELISA (DAS-ELISA) was compared with other conventional test for the diagnosis of staphylococcal mastitis taking cultural examination as standard test. Milk samples from 279 functional quarters from 72 apparently healthy cows were screened. Out of 105 staphylococci positive quarter milk samples 60.95%, 40.95%, 56.19%, 66.67%, 74.29% and 34.29% quarter milk samples were found true positive by California mastitis test (CMT), Electrical conductivity (EC), NAGase activity in milk, somatic cell count (SCC), DAS-ELISA (S. aureus) and DAS-ELISA (S. epidermidis), respectively. DAS-ELISA specific for S. aureus was found to be the most sensitive (74.29%) showing highest predictive value of negative test (83.54%) followed by SCC, CMT, NAGase activity, EC and DAS-ELISA (S. epidermidis). DAS-ELISA specific for S. epidermidis was found highly specific (100%) and showed highest predictive value of positive test (100%). Whereas, the specificity of other test was followed as EC, CMT, SCC, DAS-ELISA (S. aureus) and NAGase test. The predictive value of positive test was followed by CMT, SCC, EC, DAS-ELISA (S. aureus) and NAGase test. From the study, it can be concluded that DASELISA for the screening of herd for staphylococcal mastitis can be used in adjunct to cultural examination and large herd can be screened in a very short period of time.