Investigation of the Incidence and Diagnosis of Subclinical Mastitis in Early Lactation Period Cows

Abstract: The aim of this study was to compare the results of the California mastitis test (CMT) and bacteriological culture for detection of subclinical intramammary infections after 10 days postpartum. Samples were collected from 102 cows. The CMT was performed once on each cow. The results of bacteriological culture and the CMT were compared in 344 milk samples. Two hundred fifty samples were CMT (+) and 94 samples were CMT (-); 224 samples were bacteriologic culture (+) and 120 samples were culture (-). Both CMT and culture (+) samples numbered 212, CMT and culture (-) samples 82, CMT (+) and culture (-) samples 38, and CMT (-) and culture (+) samples 12. Sensitivity of the CMT score was 94%, specificity was 68%, positive predictive value was 84%, negative predictive value was 87%, and accuracy rate was 85%. In conclusion, the prevalence of subclinical mastitis in the early lactation period was high and the CMT was a reliable method for its detection in this period.