Fig. 2

Effect of supplementary carnitine on hepatic metabolome profiles of Holstein cows on d 100 postpartum (before LPS injection). A, Hepatic metabolome profiles of cows with (CAR group) or without (CON group) supplementary carnitine by PLS-DA scores plot. B, Top 15 important hepatic metabolites of the first PLS-DA component. C, The accuracy, the goodness of fit (R²), and predictive ability (Q²) of the PLS-DA model as assessed by cross-validation. In plot B, the blue and red squares indicate lower and higher metabolite concentrations, respectively. Cx: Acylcarnitines of x chain length; PC: Phosphatidylcholine; SM: Sphingomyelin; lysoPC: Lysophosphatidylcholine. The specific abbreviations of these metabolites are available in Additional file 1: Table S1