(1)H-Nuclear Magnetic Resonance-Based Plasma Metabolic Profiling of Dairy Cows with Fatty Liver.

Fatty liver is a common metabolic disorder of dairy cows during the transition period. Historically, the diagnosis of fatty liver has involved liver biopsy, biochemical or histological examination of liver specimens, and ultrasonographic imaging of the liver. However, more convenient and noninvasive methods would be beneficial for the diagnosis of fatty liver in dairy cows. The plasma metabolic profiles of dairy cows with fatty liver and normal (control) cows were investigated to identify new biomarkers using (1)H nuclear magnetic resonance. Compared with the control group, the primary differences in the fatty liver group included increases in ß-hydroxybutyric acid, acetone, glycine, valine, trimethylamine-N-oxide, citrulline, and isobutyrate, and decreases in alanine, asparagine, glucose, γ-aminobutyric acid glycerol, and creatinine. This analysis revealed a global profile of endogenous metabolites, which may present potential biomarkers for the diagnosis of fatty liver in dairy cows.

Effect of NEFA and glucose levels on CPT-I mRNA expression and translation in cultured bovine hepatocytes.

The objective of this study was to determine the effects of NEFA and glucose on carnitine palmitoyltransferase-I (CPT-I) mRNA expression in cultured bovine hepatocytes using real-time reverse transcription polymerase chain reaction and ELISA methods. The results indicated that CPT-I transcription increased gradually, but that CPT-I translation was not significantly changed, with glucose concentrations ranging from 0 to 3.0 mmol/L (P<0.01). Furthermore CPT-I transcription and translation were enhanced significantly when the NEFA concentrations increased from 0 to 1.2 mmol/L and decreased significantly when the NEFA concentrations increased from 1.2 to 4.8 mmol/L (P<0.01). A high concentration NEFA was found to reduce fatty acid oxidation, potentially explaining the development from NEB to ketosis in dairy cows.

Predictive Value of Plasma Parameters in the Risk of Postpartum Ketosis in Dairy Cows.

INTRODUCTION: The predictive value of selected parameters in the risk of ketosis and fatty liver in dairy cows was determined. MATERIAL AND METHODS: In total, 21 control and 17 ketotic Holstein Friesian cows with a ß-hydroxybutyrate (BHBA) concentration of 1.20 mmol/L as a cut-off point were selected. The risk prediction thresholds for ketosis were determined by receiver operating characteristic (ROC) curve analysis. RESULTS: In the ketosis group, paraoxonase-1 (PON-1) activity and concentration of PON-1 and glucose (GLU) were decreased, and aminotransferase (AST) activity as well as BHBA and non-esterified fatty acid (NEFA) contents were increased. The plasma activity and concentration of PON-1 were significantly positively correlated with the level of plasma GLU. The plasma activity and concentration of PON-1 were significantly negatively correlated with the levels of AST and BHBA. According to ROC curve analysis, warning indexes of ketosis were: plasma PON-1 concentration of 46.79 nmol/L, GLU concentration of 3.04 mmol/L, AST concentration of 100 U/L, and NEFA concentration of 0.82 mmol/L. CONCLUSION: This study showed that the levels of PON-1, GLU, AST, and NEFA could be used as indicators to predict the risk of ketosis in dairy cows.

Serum Paraoxonase as an Indicator for Fatty Liver in Sheep.

INTRODUCTION: A model of fatty liver in postpartum sheep was established to measure blood paraoxonase 1 (PON1) and other biochemical indicators, which were used to predict fatty liver in sheep. MATERIAL AND METHODS: Sheep were assigned into two experimental groups: a fatty liver group (T, n = 10) and a healthy control group (C, n = 5). PON1 enzyme activity towards paraoxon as a substrate was quantified spectrophotometrically. The results were analysed by t-test and pearson correlation coefficient. Disease was predicted by binary logistic analysis, and diagnostic thresholds were determined by receiver operatingcharacteristic (ROC) analysis. RESULTS: The activity of serum PON1 in group T was significantly decreased (P < 0.05) when compared with C group, and liver lipid content and the levels of serum BHBA, NEFA, and TG were significantly increased (P < 0.05). Thresholds were lower than 74.0 U/mL for PON1, higher than 0.97 mmol/L for ß-hydroxybutyrate, higher than 1.29 mmol/L for non-esterified fatty acids, higher than 0.24 mmol/L for triglycerides, and lower than 71.35 g/L for total protein. CONCLUSION: This study verified that PON1, BHBA, NEFA, TG, and TP could be used to predict the risk of fatty liver in sheep.