Достижения в молочных исследованиях
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ISSN: 2329-888X
ISSN: 2329-888X
Shuoshuo Xu, Zhaohai Wu, Yang Zou, Shengli Li and Zhijun Cao
The objective of this study was to evaluate the performance of a new cowside test in detecting sub-clinical ketosis (SCK) by comparing β-hydroxybutyrate (BHBA) concentrations obtained using a new hand-held meter, TNN (Yicheng Co., Beijing, China), with those obtained from the conventional laboratory method and to compare the accuracy of using blood, urine and milk samples for diagnostic purposes. TNN is based on an enzymatic electrochemical technique to detect SCK in dairy cows. 297 samples of blood, 97 samples of urine and 85 samples of milk from clinically healthy Holstein cows from d 1 to 58 post-partum were analyzed. The correlation coefficients for BHBA with TNN versus laboratory method were 0.98. Based on Bland-Altman plot, agreement between the two methods was good for BHBA. In this study, the TNN test had sensitivities of 91.4 and 96.8% at 1.2 and 1.4 mmol of BHBA/L, respectively of whole blood. While the specificities were 97.3% and 98.5%, at 1.2 and 1.4 mmol of BHBA/L, respectively. When compared with TNNthe sensitivities and specificities of urine and milk tests were lower. The sensitivities and specificities were 57 and 80% for milk tests, respectively, and 71% and 94% for urine tests, respectively, when 1.2 mmol/L of blood was defined as the threshold. Raising the threshold of laboratory method to 1.4 mmol/L, the sensitivities and specificities was 75 and 79% for milk tests, and 75 and 93% for urine tests, respectively. We concluded that TNN was a useful tool in diagnosis of SCK and blood tests were better than urine and milk tests.