Characterization of the serum metabolic profile of dairy cows with milk fever using 1H-NMR spectroscopy

Background: Milk fever (MF) is a common calcium metabolism disorder in perinatal cows. Currently, information regarding the detailed metabolism in cows suffering from MF is scant. Objective: The purpose was to study the metabolic profiling of serum samples from cows with MF in comparison to control cows, and thereby exploring other underlying pathological mechanisms of this disease. Animals and methods: In the current study, we compared the serum metabolomic profile of dairy cows with MF (n = 8) to that of healthy dairy cows (n = 24) using a 500-MHz digital H-1-nuclear magnetic resonance (H-1-NMR) spectrometer. Based on their clinical presentation and serum calcium concentration, cows were assigned either to the control group (no MF symptoms and serum calcium concentration >2.5mmol/L) or to the MF group (MF symptoms and serum calcium concentration <1.4mmol/L). For statistical analysis, a one-way analysis of variance was performed. Results: We identified differences regarding nine metabolites between the two groups, among which glucose, alanine, glycerol, phosphocreatine, and gamma-aminobutyrate decreased, and beta-hydroxybutyrate, acetone, pyruvate, and lysine increased in cows with MF. Most of these were carbohydrates and amino acids involved in various energy metabolism pathways. Conclusion: The different metabolites in cows with MF reflected the pathological features of negative energy balance and fat mobilization, suggesting that MF is associated with altered energy metabolism. Clinical importance: The H-1-NMR spectroscopy can be used to understand the pathogenesis of MF and identify biomarkers of the disease.