Effects of treatments of eCG and FSH on follicular development of Haimen goats in synchronous estrus

To improve the reproduction rate of Haimen goats, this study explores the efficient and practical breeding technology involving the combined follicle-stimulating hormone (FSH) and equine Chorionic Gonadotropin (eCG) treatment on goats in synchronous estrus. In this study, 100 IU of eCG was added to the conventional FSH superovulation regimen, enzyme-linked immunosorbent assays (ELISA) were performed to assess plasma hormone levels, Immunohistochemistry (IHC) and Hematoxylin and Eosin (HE) staining to examine ovarian tissue morphology, and transcriptome sequencing to analyze follicle granulosa cells (GCs) function, aiming to elucidate the impact of combined eCG /FSH treatment on goat follicular development. The results demonstrated that both the eCG_FSH and FSH regimen were effective in inducing superovulation in goats. Addition of 100 IU of eCG significantly enhanced concentrations of plasma follicle-stimulating hormone receptors (FSHR), progesterone (P4), and estrogen (E2), notably increasing ovulation rate and the number of antral follicles, and maintaining normal follicular morphology throughout various stages of development in goats. Furthermore, transcriptome analysis of follicle GCs showed FSH may play a significant role in promoting follicle development, ovarian growth, and estrogen synthesis by regulating key genes such as <italic>PBX1</italic>, <italic>PAPPA</italic>, and <italic>SCARB1</italic>, as well as signaling pathways like TGF-β and MAPK signaling pathways; eCG may play a crucial role in promoting follicle development and corpus luteum formation by regulating key genes such as <italic>THBD</italic>, <italic>TIMP1</italic>, and <italic>OXT</italic>, as well as signaling pathways like PI3K/Akt and cell adhesion molecules. This study comprehensively analyzed the impact of eCG/FSH on the reproductive performance of Haimen goats during synchronized estrus, laying a foundation for further investigations into the regulatory mechanisms of livestock reproduction.