Superovulation with eCG alone or combined with the GnRH analogue buserelin improves transferable embryo production in weaned sows without affecting embryo quality
The objective of this study was to evaluate the effects of eCG administered alone or in combination with buserelin (BU) on ovulatory response, embryo production efficiency, developmental synchrony, and blastocyst transcriptomic profiles in weaned donor sows. The experiment comprised six trials, each conducted over a 1-week period with 8-14 sows. A total of 76 sows selected at weaning were randomly assigned to three experimental group: eCG group (n = 27); eCG + BU group (n = 29); and control group (n = 20). Sows in the eCG group received 1000 IU of equine chorionic gonadotropin (eCG, Folligon®, Intervet International B.V., Boxmeer, The Netherlands) 24 hours post-weaning to induce superovulation. Sows in the eCG + BU group received the same eCG treatment, followed by 10 µg of BU (2.5 mL Receptal®, Merck Sharp & Dohme Animal Health, S.L., Salamanca, Spain) at the onset of estrus. Control sows received no hormonal estimulation and were monitored for spontaneous estrus post-weaning.  In vivo-developed embryos were surgically recovered on Day 6 after estrus. Four independent pools of 5 viable blastocysts per group (total n=20 blastocysts per group) were prepared for transcriptome analysis. Embryos were placed in sterile microcentrifuge tubes with 5 µL of PBS, immediately immersed in LN2 and stored at -80 °C until RNA extraction and subsequent RNA-seq analysis. After analysis, data were processed and normalized, and differentially expressed genes (DEGs) were identified for each hormonal treatment compared with the control. DEG lists were compared to identify treatment-specific gene expression changes. Pathway enrichment analysis was performed for each DEG list.
The objective of this study was to evaluate the effects of eCG administered alone or in combination with buserelin (BU) on ovulatory response, embryo production efficiency, developmental synchrony, and blastocyst transcriptomic profiles in weaned donor sows. The experiment comprised six trials, each conducted over a 1-week period with 8-14 sows. A total of 76 sows selected at weaning were randomly assigned to three experimental group: eCG group (n = 27); eCG + BU group (n = 29); and control group (n = 20). Sows in the eCG group received 1000 IU of equine chorionic gonadotropin (eCG, Folligon®, Intervet International B.V., Boxmeer, The Netherlands) 24 hours post-weaning to induce superovulation. Sows in the eCG + BU group received the same eCG treatment, followed by 10 µg of BU (2.5 mL Receptal®, Merck Sharp & Dohme Animal Health, S.L., Salamanca, Spain) at the onset of estrus. Control sows received no hormonal estimulation and were monitored for spontaneous estrus post-weaning.  In vivo-developed embryos were surgically recovered on Day 6 after estrus. Four independent pools of 5 viable blastocysts per group (total n=20 blastocysts per group) were prepared for transcriptome analysis. Embryos were placed in sterile microcentrifuge tubes with 5 µL of PBS, immediately immersed in LN2 and stored at -80 °C until RNA extraction and subsequent RNA-seq analysis. After analysis, data were processed and normalized, and differentially expressed genes (DEGs) were identified for each hormonal treatment compared with the control. DEG lists were compared to identify treatment-specific gene expression changes. Pathway enrichment analysis was performed for each DEG list.