A better understanding of the impacts of metabolic status of the cow on biological systems directly involved in the development of oocytes provide biomarkers associated with follicular and oocyte quality, which can be used as new traits for genetic or genomic selection.
Research on follicular fluid microRNA sequences funded by FECUND aims to unravel molecular pathways regulated by microRNAs which are associated with oocyte developmental competence.
Oocyte developmental competence is correlated with antral follicle count (AFC) through ill-defined mechanisms. In particular, oocytes from ovaries with a lower AFC (low group) show reduced competence compared with those from ovaries with an higher AFC (high group). Moreover, the low group has reduced ovarian function traits which are similar to those typical of human ovarian diseases such us Premature Ovarian Failure (POF) and Polycystic Ovarian Syndrome (PCOS). Several circulating microRNAs have been associated to these diseases as well as dynamic changes in microRNAs have been described during oogenesis and folliculogenesis in several species including cattle. However, their role in the acquisition of developmental potential is still unclear.
Another study carried out under FECUND project aims to profile circulating microRNAs (miRNAs) in order to study the impact of lactation on miRNA profile in lactating vs non lactating dairy cows during early pregnancy and identify potential biomarkers of early pregnancy, independent of the metabolic status of dairy cows. Lactation induces changes in the metabolic status of postpartum dairy cows that impacts negatively on the likelihood of pregnancy establishment. At present, the biological factors that cause the high frequency of embrionic loss are still unclear.
Both of the research findings were presented at the 2016 Annual Conference of the IETS, in January 2016 at Louisville, Kentucky.