Efficacy of different cow side tests for diagnosis of ketosis in lactating cows

Abstract

The aim of this work was to compare the efficacy of different cow side tests for diagnosis of ketosis including Precision Xtra ketone method and PortaBHB milk ketone tests in Holstein-Friesian dairy cows. The colorimetric estimation of serum BHBA at a cutoff point ≥1.200 mmol /L was used as a gold standard method. For that purpose, 200 Holstein-Friesian dairy cows up to 6 weeks postpartum were tested. The prevalence of ketosis was 11% by using colorimetric method. The apparent prevalence of ketosis was 12.5% by using of Precision Xtra ketone test at a cutoff point of blood BHBA ≥1.200 mmol /L with 90.9% sensitivity, 97.2% specificity, 80 % positive predictive value (PPV) and 98.9% negative predictive value (NPV). A significant correlation (r = 0.871; P <0.01) was recorded between serum BHBA measured by colorimetric method and whole blood BHBA measured by Precision Xtra ketone test. The apparent prevalence of ketosis was 20.5% and 6.5% by using PortaBHB milk ketone test at a cutoff point 100-200 μmol of milk BHBA /L with 86.4% and 45.5% sensitivity, 87.6% and 98.3% specificity, 46.3% and 76.9% PPV and 98.1% and 93.6% NPV, respectively. It was concluded that Precision Xtra ketone test and PortaBHB milk ketone test are simple and rapid tools for diagnosis of ketosis compared with the standard colorimetric method. However, Precision Xtra ketone test is more accurate and sensitive than PortaBHB milk ketone test.