BLOOD PLASMA METABOLOMICS PREDICTS PREGNANCY IN HOLSTEIN CATTLE TRANSFERRED WITH FRESH AND VITRIFIED/WARMED EMBRYOS PRODUCED IN VITRO

Metabolomics may identify biomarkers in blood that differentiate pregnant from open embryo recipients. Fresh and vitrified/warmed, in-vitro produced embryos, were transferred to Holstein recipients (discovery group). Recipient blood plasma collected on Day-0 (estrus) and Day-7 (before embryo transfer) was analysed by nuclear magnetic resonance, (N=36 metabolites quantified). Metabolites whose concentrations differed between open and pregnant recipients were analysed [(P 0.650; T-Test P<0.05; Random Forests, mean decrease accuracy) and cross-validated in independent Holstein, beef and crossbred recipients (overall classification accuracy –OCA-; P<0.05). Recipients with fresh embryos showed N=6 biomarkers consistently on Day-40, Day-62 and at birth. Recipients with vitrified embryos showed N=5 biomarkers on Day-40 and Day-62 but only one biomarker at birth. The most predictive biomarkers identified at birth within fresh embryos were O...