Fig. 5

Orthogonal partial least squares discriminant analysis of the metabolomic data at T1. a Scatter plot visualising the principal components of the supervised orthogonal partial least squares discriminant analysis (OPLS-DA) of the metabolomic data from the plasma samples collected on day 16 ± 0.6 (T1) of age after the removal of outliers. Each data point is represented by its coordinates in two components: predictive latent variable (pLV) and orthogonal latent variable (oLV). The data points belonging to the normal pigs (NORM) are plotted in blue, and those belonging to pigs affected by intrauterine growth restriction (IUGR) are plotted in red. The samples group together according to the IUGR/NORM status in the scatter plot of the OPLS-DA first principal plan. b OPLS-DA loadings plot of the metabolomic data from the plasma samples collected at T1 after the removal of outliers; x-axis: metabolites present in the plasma; y-axis: loadings for each metabolite. Loadings indicate the contribution of each metabolite to the separation between the two groups: pigs affected by intrauterine growth restriction (IUGR) and normal pigs (NORM). Positive loadings indicate that higher levels of the metabolite are associated with the NORM groups, while negative loadings indicate higher levels in the IUGR group. The metabolites with the highest positive and negative loadings contribute the most to the separation between the two groups