Nuclear magnetic resonance and mass spectrometry-based milk metabolomics in dairy cows during early and late lactation

Abstract

Milk production in dairy cows has dramatically increased over the past few decades. The selection for higher milk yield affects the partitioning of available nutrients, with more energy being allocated to milk synthesis and less to physiological processes essential to fertility and fitness. In this study, the abundance of numerous milk metabolites in early and late lactation was systematically investigated, with an emphasis on metabolites related to energy metabolism. The aim of the study was the identification and correlation of milk constituents to the metabolic status of the cows. To investigate the influence of lactation stage on physiological and metabolic variables, 2 breeds of different productivity were selected for investigation by high-resolution nuclear magnetic resonance spectroscopy and gas chromatography-mass spectrometry. We could reliably quantify 44 different milk metabolites. The results show that biomarkers such as acetone and beta-hydroxybutyrate are clearly correlated to the metabolic status of the individual cows during early lactation. Based on these data, the selection of cows that cope well with the metabolic stress of early lactation should become an option.

Effects of continuous milking during a field trial on productivity, milk protein yield and health in dairy cows

“…Metabolic situation How sensitively cows react on increased blood parameters and how they can compensate the metabolic stress depends on the genetic disposition (Klein et al, 2010). Concerning the BHBA, NEFA, calcium, IGF-1 blood concentration and the changes of the back fat thickness, a clear interference of the milking regimen could be shown.…”

Correlations between Milk and Plasma Levels of Amino and Carboxylic Acids in Dairy Cows

“…The table also lists the corresponding, previously determined levels of the 27 metabolites in milk, while Supplemental Table S1 gives the concentrations of seven additional metabolites measured by NMR in milk only. 21 The majority of metabolites could be detected above their respective LLOQs in all blood specimens. Exceptions were asparagine, aspartate, fumarate, glutamine, histidine, methionine, pyruvate, and threonine (Table 1).…”

“…23 GC−MS of β-Hydroxybutyrate, Glucose, and Citrate Cycle Intermediates Quantitative analysis of BHBA, glucose, pyruvate, lactate, and intermediates of the citrate cycle was performed in 10-μL aliquots of plasma that were subjected to online methoximation/ silylation in the presence of stable isotope-labeled internal standards and GC−MS on a Pegasus GC−electron ionization (EI)−timeof-flight (TOF)−MS instrument (Leco, St. Joseph, MI, USA) as described previously. 21 …”

“…21 Significant correlations were observed between the branched-chain AA (BCAA) isoleucine, leucine, and valine in plasma. Mammary cells catabolize BCAA to generate organic acids including α-ketoglutarate and oxaloacetate, which are transaminated to glutamate and aspartate.…”

“…20 The present study builds on our recent analysis of different milk metabolites by high-resolution NMR and gas chromatography− mass spectrometry (GC−MS) in two different breeds of dairy cows, namely, Brown Swiss and Simmental, during early and late lactation. 21 Here, 27 metabolites that had been detected in milk by GC−MS were analyzed in blood plasma, and their levels were correlated to those previously determined in milk collected at the same time. Albeit not the first study of its kind, it exceeds previous investigations on relationships between concentrations of metabolites in blood and milk with regard to either the number of animals and/or the number of metabolites studied and extends them beyond the first few weeks of lactation.…”