Bach K D, Heuwieser W, McArt J A A
Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853.
Clinic for Animal Reproduction, Faculty of Veterinary Medicine, Freie Universität Berlin, 14163 Berlin, Germany.
J Dairy Sci. 2016 Nov;99(11):9136-9142. doi: 10.3168/jds.2016-11077. Epub 2016 Aug 24.
The objective of this study was to evaluate 4 handheld ketone meters for use in on-farm β-hydroxybutyrate (BHB) monitoring of hyperketonemia in transition dairy cows. Blood samples taken from 250 Holstein cows between 262d pregnant and 15d in milk were evaluated on 4 different handheld ketone meters: Precision Xtra (Abbott Laboratories, Abbott Park, IL), TaiDoc (Pharmadoc, Lüdersdorf, Germany), Nova Max (Nova Biomedical, Billerica, MA), and Nova Vet (Nova Biomedical). Samples were screened using the Precision Xtra and tested on the remaining 3 m if the sample BHB concentration fell into predetermined ranges. A total of 89 samples were used for analysis. Performance of each meter was compared with the average of 2 plasma BHB concentrations both determined by a gold standard spectrophotometric Randox assay performed at 2 independent laboratories. Agreement between the 2 laboratories was very strong (Pearson correlation=0.998). All meters had Pearson correlation coefficients greater than 0.95. The Precision Xtra and TaiDoc meters were 100.0% sensitive and 73.5% specific at a BHB concentration cut point of 1.2mmol/L. The Nova Vet and Nova Max meters had sensitivities of 94.9 and 74.4% and specificities of 91.8 and 100.0%, respectively, at the same cut point. Agreement between the gold standard and the handheld meter was the best for the Nova Vet meter when evaluated using a Bland Altman graph with a mean BHB difference of 0.08mmol/L. Trends in bias were noted with the Precision Xtra and Nova Max meters resulting in increasing average discrepancy between the gold standard and the meter for both at higher plasma BHB concentrations and mean BHB differences of -0.34 and 0.26mmol/L, respectively. The coefficient of variation was <10% for the Precision Xtra, TaiDoc, and Nova Vet meters, and <15% for the Nova Max meter. We conclude that the TaiDoc and Nova Vet meters, similar to the already validated Precision Xtra meter, are acceptable for use in on-farm testing for monitoring and treatment of hyperketonemia.
本研究的目的是评估4种手持式酮类检测仪，用于对围产期奶牛的高酮血症进行农场现场β-羟基丁酸（BHB）监测。从250头怀孕262天至产犊后15天的荷斯坦奶牛采集血样，使用4种不同的手持式酮类检测仪进行评估：Precision Xtra（雅培实验室，伊利诺伊州雅培公园）、TaiDoc（德国吕德斯多夫Pharmadoc公司）、Nova Max（美国马萨诸塞州比勒里卡Nova Biomedical公司）和Nova Vet（Nova Biomedical）。使用Precision Xtra进行样本筛查，若样本BHB浓度落入预定范围，则在其余3种检测仪上进行检测。总共89个样本用于分析。将每种检测仪的检测结果与由2个独立实验室采用金标准分光光度法兰道克斯检测法测定的2个血浆BHB浓度的平均值进行比较。2个实验室之间的一致性非常强（皮尔逊相关系数=0.998）。所有检测仪的皮尔逊相关系数均大于0.95。在BHB浓度切点为1.2mmol/L时，Precision Xtra和TaiDoc检测仪的灵敏度为100.0%，特异性为73.5%。在相同切点时，Nova Vet和Nova Max检测仪的灵敏度分别为94.9%和74.4%，特异性分别为91.8%和100.0%。使用布兰德-奥特曼图评估时，当平均BHB差异为0.08mmol/L时，金标准与Nova Vet检测仪之间的一致性最佳。Precision Xtra和Nova Max检测仪存在偏差趋势，导致在较高血浆BHB浓度时，金标准与检测仪之间的平均差异分别增加，平均BHB差异分别为-0.34和0.26mmol/L。Precision Xtra、TaiDoc和Nova Vet检测仪的变异系数<10%，Nova Max检测仪的变异系数<15%。我们得出结论，TaiDoc和Nova Vet检测仪与已验证的Precision Xtra检测仪类似，可接受用于农场现场检测以监测和治疗高酮血症。
