Evaluation of the Diagnostic and Analytical Performance of the CentriVet Blood Ketone Monitoring System in Postpartum Dairy Cattle.

The periparturient period in dairy cows is marked by negative energy balance (NEB), resulting in metabolic stress and an increased risk of postpartum diseases. Accurate assessment of NEB through blood β-hydroxybutyrate (β-OHB) levels is essential for effective herd management. Point-of-care (POC) devices, such as the CentriVet blood ketone monitoring system, offer a practical alternative to laboratory methods for measuring β-OHB. This study aimed to evaluate the diagnostic and analytical performance of the CentriVet blood ketone monitoring system compared to a laboratory reference method for measuring blood β-OHB concentration in postpartum dairy cattle. A total of 105 postpartum dairy cows from two farms were included. Blood samples were analyzed for β-OHB using both CentriVet and a reference enzymatic method. Passing-Bablok regression, Bland-Altman plots, and kappa statistics were used to assess agreement. Diagnostic accuracy metrics (sensitivity, specificity, PPV, NPV, and accuracy) were calculated at a cut-off value of ≥ 1.2 mmol/L. An optimized cut-off value was determined via ROC curve analysis. CentriVet demonstrated a moderate correlation with the reference method (Spearman's r = 0.701, p < 0.001). Passing-Bablok regression revealed proportional bias, and Bland-Altman analysis indicated a mean bias of -0.4 mmol/L. Diagnostic metrics at ≥ 1.2 mmol/L showed 100% sensitivity, 68.09% specificity, and 71.4% accuracy. ROC analysis yielded an optimized cut-off of > 1.5 mmol/L, improving specificity (95.7%) but reducing sensitivity (81.8%). While CentriVet offers practical benefits, its diagnostic performance is limited for accurately identifying hyperketonemia in postpartum dairy cattle.