Supplementary data to publication "Untargeted metabolomics reveals metabolic stress alleviation by prepartum exercise in transition dairy cows"

Prepartum exercise is one of the methods of optimizing perinatal management practices to improve health. However, mechanism of prepartum exercise regulates on metabolism are rarely been described. The objective of this study was to investigate metabolic changes in transition cows with exercise. 24 Holstein transition dairy cows were assigned to exercise (n = 12) and control group (n = 12) on approximately d 21 prepartum, plasma was collected during -21, -7, 0, +7, and +30 d relative to calving. The researchers assisted the exercise group cows to walk for a targeted 45 min at 3.25 km/h, 2 times/d. Plasma non-esterified fatty acid (NEFA), β-hydroxybutyric acid (BHBA), glucose, and triglycerides were evaluated, and metabolic profile was analyzed using ultra-high-performance liquid chromatography time-of-flight mass spectrometry. The results demonstrated that concentrations NEFA at -7 d, glucose at 0d, and BHBA at +7d relative to calving were obviously reduced in exercise cows. Untargeted metabolomics analyses showed that cows had experienced severe metabolic stress during calving, including increased fatty acid and glucose metabolism, and reduced bile acid and tryptophan metabolism. Four key metabolites were identified in cows with exercise during metabolic stress: gentisic acid, kynurenine, homovanillic acid, and cis-9-palmitoleic acids. Correlation and pathway analysis indicated that exercise had down-regulation of NEFA and BHBA production and maintained glucose levels through tryptophan-kynurenine metabolism, improving postpartum health.