Fig. 4

Effects of late gestational HS on the fecal metabolomic profiles of primiparous sows. a Orthogonal-partial least squares projection to latent structures and discriminant analysis (OPLS-DA) based on the fecal compounds data. The OPLS-DA score plots discriminating the feces of primiparous sows treated between TN (green) and HS (red) condition during late gestation [predictive ability parameter (Q²) (cum) = 0.813, goodness-of-fit parameter (R²) (X) = 0.872]. b Significant compounds. Metabolites accountable for class discrimination with VIP > 1, |log₂ fold change| > 0.585, and P < 0.05 were listed. c metabolome view map of the differential metabolites (VIP > 1, P < 0.05) identified in the feces of primiparous sows treated between TN and HS condition during late gestation. The x-axis represents the pathway impact and the y-axis represents the pathway enrichment. The node color is based on its P-value, and the node radius is determined based on the pathway impact values. Larger sizes and darker colors represent higher pathway enrichment and impact values, respectively (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article). HS = heat stress; TN = thermoneutral