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

Prepartum exercise has been proposed
as an optimal strategy for peripartum management to improve the health of dairy
cows.
However, the mechanism by which prepartum exercise impacts metabolism has not
been described in detail. Therefore, the objective of this study was to
investigate metabolic changes in transition dairy cows with and without prepartum exercise. Twenty-four Holstein transition multiparous dairy
cows were assigned to an exercise (n = 12) or control (n = 12) group, and
plasma was collected at –21, –7, 0, +7, and +30 d relative to calving. The
cows in the exercise group walked with the assistance of the researchers 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 triglyceride levels
were measured, and metabolic profiles were analyzed using ultra-high-performance
liquid chromatography time-of-flight mass spectrometry. Compared with those of the control
group, the concentrations of NEFA at –7
d, glucose at 0 d, and BHBA at +7 d relative to calving were markedly
decreased
in the exercised group. Untargeted metabolomics and pathway analyses showed differences
in the levels of key metabolites and their upstream metabolites between exercise
and control cows, including gentisic acid, kynurenine, Trp, homovanillic acid, dopamine,
cis-9-palmitoleic acid, and palmitic acid. Correlation and fold change analyses
indicated that prepartum exercise may decrease homovanillic acid and
cis-9-palmitoleic acid levels and increase tryptophan and gentisic acid levels
to alleviate the metabolic stress of dairy cows during the transition period.