Serum Metabolomic Analysis of Synchronous Estrus in Yaks Based on UPLC-Q-TOF MS Technology.

Simple Summary: The synchronization process of yak estrus plays a crucial role in enhancing the reproductive success rate of yaks and safeguarding the continuation of the species. Metabolomics, a branch of bio-chemistry, primarily focuses on the quantitative analysis of all metabolites within an organism, aiming to identify the relative relationships between metabolites and physiological changes. It serves as a valuable tool for delving into the molecular mechanisms and responses of metabolic pathways under various perturbations. In this study, metabolomics methods were utilized to analyze blood samples collected from non-estrus yaks as well as those that underwent hormonally induced synchronized estrus to identify differential metabolites. The research results provide a theoretical basis for the optimization and application of synchronized estrus technology in yaks, promoting the healthy development of the yak industry. The yak is a unique species of livestock found in the Qinghai-Tibet Plateau and its surrounding areas. Due to factors such as late sexual maturity and a low rate of estrus, its reproductive efficiency is relatively low. The process of estrus synchronization in yaks plays a crucial role in enhancing their reproductive success and ensuring the continuation of their species. In order to clarify the characteristics of the serum metabolites of yak estrus synchronization, the yaks with inactive ovaries were compared with the estrus synchronization yaks. In this study, yaks were divided into the inactive ovaries group (IO), gonarelin-induced yak estrus group (GnRH), and chloprostenol sodium-induced yak estrus group (PGF). After the completion of the estrus synchronization treatment, blood samples were collected from the jugular veins of the non-estrus yaks in the control group and the yaks with obvious estrus characteristics in the GnRH and PGF groups. Metabolites were detected by ultra-high performance liquid chromatography-mass spectrometry, and differential metabolites were screened by multivariate statistical analysis. The results showed that a total of 70 significant differential metabolites were screened and identified in the GnRH vs. IO group, and 77 significant differential metabolites were screened and identified in the PGF vs. IO group. Compared with non-estrus yaks, 36 common significant differential metabolites were screened out after the induction of yak estrus by gonarelin (GnRH) and cloprostenol sodium (PGF), which were significantly enriched in signaling pathways such as the beta oxidation of very long chain fatty acids, bile acid biosynthesis, oxidation of branched chain fatty acids, steroidogenesis, steroid biosynthesis, and arginine and proline metabolism. This study analyzed the effects of gonadotropin releasing hormone (GnRH) and prostaglandin F (PGF) on the reproductive performance of yaks treated with estrus synchronization, which provides a theoretical basis for the optimization and application of yak estrus synchronization technology and promotes the healthy development of the yak industry. [ABSTRACT FROM AUTHOR]