Figure 6.

Spearman correlation heatmaps (a) for the correlations between phenotypic variables (NEFA, BHBA, TG, and glucose) and key differential metabolites in the exercise and control cows. The scale (right legend) indicates the level of positive (red) or negative (blue) correlations, and asterisks indicate significance: * p < 0.05, ** p < 0.01. PLA/PA = cis-9-palmitoleic acid to palmitic acid ratio; HVA/DA = homovanillic acid to dopamine ratio; Kyn/TRP = kynurenine to tryptophan ratio; NEFA = non-esterified fatty acids; BHBA = β-hydroxybutyric acid; TG = triglyceride. Box plots (b) for the relative abundance of tryptophan and kynurenine, and Kyn/Trp in the exercise and control cows at −7 d, 0 d, +7 d, and +30 d relative to calving.