Department of Veterinary Clinical Medicine, Ethics and Jurisprudence, CCS Haryana Agricultural University, Hisar-125004, (Haryana), INDIA.
A comparative study of different indirect diagnostic tests was undertaken for the detection of sub-clinical mastitis (SCM). Out of 279 quarter milk samples from 72 apparently healthy lactating crossbred cows, 89, 63, 98, 102 and 118 were tested positive for SCM by CMT, electrical conductivity, NAGase activity in milk, somatic cell count (SCC) and cultural examination, respectively. SCC revealed highest sensitivity (69.49%) and predictive value of negative test (79.66%). All the tests except for NAGase test showed almost similar specificity. The predictive value of positive tests was higher in CMT (80.90%) and SCC (80.39%) as compared to EC (71.42%) and NAGase test (67.35%). CMT and SCC can be used as a preference screening field and laboratory test for selecting cows with intramammary infections for subsequent bacteriological sampling.
Bovine, sub-clinical mastitis, CMT, electrical conductivity, NAGase activity, somatic cell count, cultural examination
