Biomarkers predictive of long-term fertility found in vaginal lipidome of gilts at weaning

Abstract Background A marker indicative of fertility potential of replacement gilts early in development would decrease culling rates in the sow herd, improve sow herd reproductive efficiency, and reduce production costs. The objective of this study was to determine if vaginal lipid profiles at 21 d postnatal (PN) could predict sow reproductive performance. Methods Vaginal swabs of the anterior vagina were taken at 21 ± 4 d PN from gilts born on a commercial sow production facility for lipidomic analysis. Animals were followed prospectively for two years and assigned to reproductive performance categories based on observation of estrus or piglets weaned per sow per year (PSY) across two farrowings. Results Lipids were extracted from cellular material collected with swabs taken from high fertility (HF; n = 28; ≥26 PSY) and infertile (IF; n = 34; no estrus, no pregnancy) animals and multiple reaction monitoring (MRM) profiling was used for lipidome analysis. Relative abundance of arachidonic acid (ARA, C20:4) and docosahexaenoic acid (DHA, C22:6) were lower (P < 0.05) in IF gilts than HF gilts, whereas abundance of the free fatty acids cerotic (C26:0), ximenic (C26:1), and nonadecanoic (C19:0) acids were greater (P < 0.05) in IF gilts. Additionally, eicosapentaenoic acid (C20:5) a precursor of prostaglandins was also higher (P < 0.05) in IF gilts. Conclusions The perspective of having a panel of lipids captured with vaginal swabs at weaning that can predict reproductive efficiency of gilts shows promise and warrants future research in this area.