Milk metabolomics based on ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry to discriminate different cows feeding regimens

Abstract The feeding system represents one of the main factors driving raw milk composition, thus determining differences in nutritional value and technological properties. In this preliminary study, untargeted metabolomics with ultra-high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC-QTOF) coupled with both unsupervised and supervised multivariate statistics was used to investigate the chemical profile of bulk milk collected from dairy cows (n = 103) following different feeding regimens, being corn silage (MS-FS, n = 51), hay (H-FS, n = 35) and a mixed ration consisted in fresh forage and hay (MR-FS, n = 17). Overall, a total of 1686 metabolites was identified by means of UHPLC-QTOF, with significant differences (p