Validation of A Portable Beta-Hydroxybutyric Acid Analyser for The Diagnosis of Subclinical Ketosis in Dairy Cows

Authors : Kemal Aksoy, Abdülkerim Deniz, Mert Metin, Gülten Emek Tuna

Pages : 317-325

Doi:10.30607/kvj.1310055

View : 116 | Download : 155

Publication Date : 2023-09-30

Article Type : Research

Abstract :On-farm determination of beta-hydroxybutyric acid (BHBA) with an accurate analyser is important for rapid diagnosis of subclinical ketosis (SCK) or clinical ketosis in dairy cows. The accuracy of the Taidoc BHBA portable analyser has not yet been tested and validated. The objective was the validation of the Taidoc BHBA analyser with another device Wellion (already validated) in 84 dairy cows. Whole blood was collected from the coccygeal vein and immediately analysed with Taidoc and Wellion in one drop of whole venous blood of 84 dairy cows. The averages of BHBA concentration were 0.79±0.66 and 1.09±0.51 mmol.l-1 for Wellion and Taidoc, respectively. The correlation coefficient was r=0.64 (p<0.001). Method comparison by the Passing-Bablok regression equation (y=0.0664+0.06111x) showed no agreement between the two instruments. The intercept A and slope B did not include 0.0 and 1.0, respectively. The Bland-Altman plots of agreement indicated that the mean deviation was 0.30 mmol.l-1 and the total deviation was 2.02 mmol.l-1, which was unacceptably high. The weighted kappa value was 0.26, indicating minimal agreement. AUC, sensitivity and specificity for the diagnosis of SCK at cut-off point ≥1.2 mmol.l-1 BHBA were 0.78, 64.7% and 91.0%, respectively. There was no agreement between the Taidoc and the Wellion BHBA portable analyser for dairy cows and they cannot be used interchangeably. Taidoc gave much higher BHBA values than Wellion and its sensitivity and specificity for SCK diagnosis was not comparable to Wellion.
Keywords : Beta-hidroksibütirik asit, Süt ineği, Subklinik ketozis, Taidoc, Wellion