[Pilot study of the Deosan-RMTK (rapid mastitis test kit), a diagnostic test for the detection of cows with high cell count].

The Deosan-Rapid Mastitis Test Kit (RMTK) was evaluated in 226 lactating dairy cows on 6 farms. The Fossomatic method was used as reference standard for somatic cell counts in cows milk. The RMTK test-principle regards the reaction of the enzyme catalase released from cells in milk with the H2O2 in the RMTK-reagent. For the threshold cell count values of 250,000, 400,000 and 800,000/ml the following 95% confidence intervals were found: sensitivity 0.60-0.99 specificity 0.42-0.83, predictive value positive 0.22-0.46, predictive value negative 0.84-0.99 and kappa-value 0.14-0.52. Because this test will be most useful when the positive predictive value would be high, it is concluded that the RMTK in this study population was not an adequate tool for the detection of cows with somatic cell counts over 250,000/ml milk.