Subclinical (SCK) and clinical (CK) ketosis are metabolic disorders responsible for big losses in dairy production. Although Fourier-transform mid-infrared spectrometry (FTIR) to predict ketosis in cows exposed to great metabolic stress was studied extensively, little is known about its suitability in predicting hyperketonemia using individual samples, e.g. in small dairy herds or when only few animals are at risk of ketosis. The objective of the present research was to determine the applicability of milk metabolites predicted by FTIR spectrometry in the individual screening for ketosis. In experiment 1, blood and milk samples were taken every two weeks after calving from Holstein (n = 80), Brown Swiss (n = 72) and Swiss Fleckvieh (n = 58) cows. In experiment 2, cows diagnosed with CK (n = 474) and 420 samples with blood β-hydroxybutyrate [BHB] <1.0 mmol/l were used to investigate if CK could be detected by FTIR-predicted BHB and acetone from a preceding milk control. In experiment 3, correlations between data from an in farm automatic milk analyser and FTIR-predicted BHB and acetone from the monthly milk controls were evaluated. Hyperketonemia occurred in majority during the first eight weeks of lactation. Correlations between blood BHB and FTIR-predicted BHB and acetone were low (r = 0.37 and 0.12, respectively, P < 0.0001), as well as the percentage of true positive values (11.9 and 16.6%, respectively). No association of FTIR predicted ketone bodies with the interval of milk sampling relative to CK diagnosis was found. Data obtained from the automatic milk analyser were moderately correlated with the same day FTIR-predicted BHB analysis (r = 0.61). In conclusion, the low correlations with blood BHB and the small number of true positive samples discourage the use of milk mid-infrared spectrometry analyses as the only method to predict hyperketonemia at the individual cow level.

中文翻译：

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基于牛奶中红外光谱的丙酮和β-羟基丁酸估计预测奶牛代谢应激和酮症的机会和局限性

亚临床 (SCK) 和临床 (CK) 酮症是导致乳制品生产大量损失的代谢紊乱。尽管傅里叶变换中红外光谱法 (FTIR) 用于预测暴露于巨大代谢压力的奶牛的酮症已被广泛研究，但对其使用个体样本预测高酮血症的适用性知之甚少，例如在小型奶牛群或只有少数动物处于酮症的风险。本研究的目的是确定 FTIR 光谱法预测的牛奶代谢物在个体酮症筛查中的适用性。在实验 1 中，从荷斯坦产犊后每两周采集一次血液和牛奶样本（n= 80), 布朗瑞士 (n= 72) 和瑞士 Fleckvieh (n= 58) 奶牛。在实验 2 中，诊断为 CK 的奶牛 (n= 474) 和 420 个血液 β-羟基丁酸 [BHB] <1.0 mmol/l 的样本用于研究是否可以通过 FTIR 预测的 BHB 和来自先前牛奶对照的丙酮检测到 CK。在实验 3 中，评估了来自农场自动牛奶分析仪的数据与来自每月牛奶对照的 FTIR 预测的 BHB 和丙酮之间的相关性。高酮血症主要发生在哺乳的前八周。血液 BHB 与 FTIR 预测的 BHB 和丙酮之间的相关性较低（r= 0.37 和 0.12，分别磷< 0.0001），以及真阳性值的百分比（分别为 11.9 和 16.6%）。没有发现 FTIR 预测的酮体与相对于 CK 诊断的牛奶取样间隔之间存在关联。从自动牛奶分析仪获得的数据与当天 FTIR 预测的 BHB 分析中度相关（r= 0.61)。总之，与血液 BHB 的低相关性和少量真阳性样本不鼓励使用牛奶中红外光谱分析作为预测个体奶牛水平高酮血症的唯一方法。