Impact of semen cryopreservation season on in vitro embryo production of prepubertal goat oocytes

Goat production is affected by reproductive seasonality. In vitro embryo production (IVEP) could overcome this effect. This study aimed to evaluate the impact of the season of semen collection/freezing on IVEP of prepubertal goat oocytes and on sperm quality and functionality concerning capacitation. Semen from six fertile bucks was collected, pooled and cryopreserved in spring and autumn and used for IVEP of oocytes recovered during the breeding season. Oocytes were IVM in TCM-199 with hormones, EGF and cysteamine; fertilized and cultured in BO-IVF and BO-IVC media (IVF Bioscience, UK). Semen samples were assessed at 0 and 3 h after culture in capacitating (BO-IVF, CAP) and non-capacitating conditions for sperm plasma membrane and acrosome integrity, mitochondrial membrane potential (MMP), intracellular calcium and plasma membrane lipid disorder. Blastocyst production was higher with spring sperm compared to autumn (12.0% vs. 2.1%, respectively; p <.05). After CAP, acrosome reaction and intracellular calcium were higher (p <.05) in spring than autumn sperm. No differences were found in other sperm parameters. In conclusion, seasonal variations in the IVEP of prepubertal goats could be linked to differences in sperm ability to undergo in vitro capacitation.