Comparison of 2 electronic cowside tests to detect subclinical ketosis in dairy cows and the influence of the temperature and type of blood sample on the test results

Abstract

The objective of this study was to determine the suitability of 2 electronic hand-held devices [FreeStyle Precision (FSP), Abbott GmbH & Co. KG, Wiesbaden, Germany and GlucoMen LX Plus (GLX), A. Menarini GmbH, Vienna, Austria] for measuring β-hydroxybutyrate (BHBA) in dairy cows. Three experiments were conducted to evaluate (1) the diagnostic performance of the devices, (2) the effect of the type of blood sample, and (3) the influence of the ambient temperature on the determined results. A total of 415 blood samples from lactating Holstein and Simmental cows were collected and analyzed with both devices (whole blood) and in a laboratory (serum). Correlation coefficients between whole-blood and serum BHBA concentrations were highly significant, with 94% for the FSP and 80% for the GLX device. Based on thresholds for subclinical ketosis of 1.2 and 1.4 mmol of BHBA/L, results obtained with the hand-held devices were evaluated by receiver operating characteristics analyses. This resulted in adjusted thresholds of 1.2 and 1.4 mmol/L for the FSP and 1.1 and 1.3 mmol/L for the GLX device. Applying these thresholds, sensitivities were 98 and 100% for the FSP and 80 and 86% for the GLX device, respectively. Corresponding specificities were 90 and 97% for the FSP and 87 and 96% for the GLX device, respectively. Additionally, concentrations of BHBA were tested with both devices in whole blood, EDTA-added whole blood, and in their resulting serum and plasma, collected from 65 animals. Determined BHBA concentrations were similar within each device for whole and EDTA-added blood, and in serum and plasma, but differed between whole blood and serum and between EDTA-added blood and plasma. Blood samples with low (0.4 mmol/L), medium (1.1 mmol/L), and high (1.6 mmol/L) BHBA concentrations were stored between +5 to +32°C and analyzed repeatedly at temperature levels differing by 4°C. Additionally, devices and test strips were stored at equal conditions and used for measurement procedures. Storage temperature of the devices and test strips did not influence the differences between the results of the laboratory and the devices, whereas the temperature of the blood samples caused significant differences. Although the level of agreement between the laboratory and the GLX device was lower than for the laboratory and the FSP device, both devices are useful tools for monitoring subclinical ketosis in dairy cows. Due to their effects on the determined results, the type and temperature of the tested sample should be considered.

Accuracy of two hand-held electronic devices for determination of blood β-hydroxybutyrate in dairy cows

“…To our knowledge, this is the first study comparing FreeStyle Optium and KetoVet systems for the measurement of BHB in dairy cattle. The correlation coefficient (r= 0.96) and the average difference (-0.01 mmol/L) between the standard method and the FSO were similar to those reported by Iwersen et al (2013) using the FSO System who founded r= 0.94 and average difference of +0.04 mmol/L and those reported by Voyvoda and Erdogan (2010) using the FSO system who reported r= 0.97 and average difference of +0.03 mmol/L. Iwersen et al (2009) evaluating the Precision Xtra meter system, which uses the same technique of the two devices used in our study, found a correlation coefficient of r= 0.95 and average difference of -0,03 mmol/L.…”

“…Iwersen et al (2009) evaluating the Precision Xtra meter system, which uses the same technique of the two devices used in our study, found a correlation coefficient of r= 0.95 and average difference of -0,03 mmol/L. While in the study of Iwersen et al (2009), the Precision Xtra system underestimated the laboratory values of BHB, the work of Iwersen et al (2013) and Voyvoda and Erdogan (2010) overestimated data of BHB using the Precision Xtra meter and FSO systems, respectively. In our study, the average difference obtained by FSO system (-0.01 mmol/L) was very close to the laboratory BHB values.…”

“…This means that portable devices possibly overestimate the BHB values. Using whole blood in portable devices and serum in spectrophotometric analysis is accepted for comparison considering the highly significant correlation coefficient (r= 0.94) between the two types of samples obtained by other authors (IWERSEN et al, 2013 Rev. Bras.…”

“…A drop of whole blood was disposed in the sample application zone of the strip, initiating an identical chemical reaction on the two devices as follows: the BHB in the sample is oxidized to acetoacetate by BHB dehydrogenase using the coenzyme NAD + that is reduced to NADH. Then, NADH is reoxidized to NAD + by a mediator, releasing electrons and generating an electric current which is directly proportional to the concentration of BHB (IWERSEN et al, 2013). The result is displayed on the screen in 5 seconds (KVE) or 10 seconds (FSO) after the application of the sample.…”

�-Hydroxybutyrate Activates the NF-κB Signaling Pathway to Promote the Expression of Pro-Inflammatory Factors in Calf Hepatocytes

“…The concentrations of BHBA used in this study were chosen according to the BHBA concentrations in cow serum [23]. Stock BHBA solution was prepared as follows: 1.206 g of BHBA powder was dissolved in 50 mL of distilled water, sterilized by filtration to obtain a concentration of 0.2 mM, and stored at -20°C.…”