Accuracy of Subclinical Ketosis Detection with Rapid Test Methods for BHBA in Blood in Commercial Dairy Farms

Abstract

This study gives an overview of the performance and accuracy of devices used for the fast measurement of β-hydroxybutyrate (BHBA) in blood for the on-farm indication of subclinical ketosis. Data were collected on ten dairy farms. In each farm, blood samples were taken from ten cows on four test days (2, 4, 9 and 11), resulting in 400 samples. The reference method was the BHBA concentration in blood serum (BHBALAB). Four different devices that measure BHBA in whole blood were tested. The thresholds applied for identifying subclinical ketosis were ≥1.0, ≥1.2 and ≥1.4 mmol/L in blood serum. The BHBALAB was assigned in three classes: low—≤0.9 mmol/L; high—>0.9 mmol/L; and total—all values unclassified. Due to initial negative effects on the health and performance of cows with BHBA levels ≥0.9 mmol/L, this cut-off was chosen. The Passing–Bablok regression revealed different constant as well as absolute biases for each device in the aforementioned classes. The area under the receiver operating characteristics curve indicated highly accurate results, with 94–97% accuracy levels. As an overall conclusion, the performance of the devices was good and supports their use by farmers for the detection of subclinical ketotic cows in their herds.

Evaluation of Freestyle Optium Neo H and TaiDoc‐TD4235 point‐of‐care meters for measuring blood β‐hydroxybutyrate concentration in sheep

“…Passing‐Bablok regression analysis indicated a negative constant (−0.19) and positive proportional bias (1.46) for the Precision Xtra meter, and a positive constant (0.22) and proportional bias (1.17) for the Taidoc meter in dairy cows 20 . In another study, Jansen et al reported a positive constant (0.092) and proportional bias (0.980) for the TaiDoc BHB‐check meter in dairy cows 5 . The Freestyle Precision meter showed neither a constant nor a proportional bias in that study.…”

“…22 However, when compared with Precision Xceed 9 and WellionVet BELUA meters, 23 the Freestyle Optium Neo H meter consistently overestimated blood β-OHB concentrations in sheep, and the overestimation is more pronounced at higher blood β-OHB concentrations. Although TaiDoc ketone meters have been previously evaluated in dairy cows, 5,20 there have been no studies evaluating TaiDoc ketone meters in sheep. In our study, the TaiDoc-TD4235 meter yielded an extremely high mean bias for blood β-OHB concentrations in sheep compared with previous studies evaluating TaiDoc meters in dairy cows and different ketone meters in sheep.…”

“…The performance of various blood ketone meters developed for human use has been evaluated in cattle, goats, and sheep for measuring blood β‐OHB concentrations 5–12 . However, in contrast with cattle studies, fewer studies have assessed the accuracy of measuring blood β‐OHB concentrations in sheep using POC devices.…”

“…The performance of various blood ketone meters developed for human use has been evaluated in cattle, goats, and sheep for measuring blood β-OHB concentrations. [5][6][7][8][9][10][11][12] However, in contrast with cattle studies, fewer studies have assessed the accuracy of measuring blood β-OHB concentrations in sheep using POC devices. To broaden the choices of clinicians, it is important to test the performance of different POC devices to measure blood β-OHB concentrations in sheep.…”

“…Laboratory analysis of serum β‐OHB concentrations is established as a gold standard method 4 . However, it is costly, time‐consuming, and may not always be available in field settings 5 . On the other hand, point‐of‐care (POC) meters have gained popularity over the past two decades to quantify blood β‐OHB concentrations due to a number of advantages, including operating with small sample volumes, lower costs, and fast results.…”