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Summary: In assisted reproductive techniques, it is essential to perform a sperm selection to obtain spermatozoa with high motility and membrane integrity for in vitro fertilisation (IVF) and high‐DNA integrity for intracytoplasmic sperm injection (ICSI). In this study, we evaluated whether Isolate® was a suitable substitute for Percoll® for assisted reproductive techniques. Commercial cryopreserved bovine semen was used after selection in both gradients, and plasma and acrosome membrane integrity, reactive oxygen species (ROS) levels, DNA integrity and mitochondrial membrane potential (ΔΨm) were assessed by flow cytometry. Motility parameters were also evaluated by CASA system. A similar percentage of spermatozoa with intact plasma membrane, acrosome integrity and high ΔΨm was observed in both sperm selection methods, but only Percoll® showed higher percentage of spermatozoa with intact plasma and acrosome membrane compared to the post‐thawing group. No differences were observed in the motility, ROS, DNA fragmentation and on the in vitro embryo production in all experimental groups. In conclusion, the selection of bovine spermatozoa with Isolate® generates spermatozoa with similar quality parameters and embryonic development compared to Percoll® providing a suitable alternative sperm selection method for assisted reproductive techniques in this species. [ABSTRACT FROM AUTHOR]

Retrospective analysis of monthly embryo production from December 2011 to May 2015 and its correlation with meteorological data in our geographic zone was made. We had observed that in certain time of the year, in vitro blastocyst production decreases. Accordingly, was examined the association between blastocyst production and climatological parameters. Cleavage rates correlate positively with blastocyst rates ( p < .05). Significant differences in cleavage rates between autumn and summer (79.8%; 71.5%), and between winter and autumn (71.8%; 79.8%), were found. Blastocyst production had lower efficiency in June (9 ± 12%) and July (4.9 ± 5.7%), which coincides with winter season. In contrast, higher embryo production was obtained in February (22.2 ± 9.7%), March (22.9 ± 14%) and September (25.2 ± 6.6%), which coincides with autumn and spring season. Similarly, embryo production correlates with meteorological parameters: blastocyst production positively correlates with sunshine hours, maximum temperature and average temperature. Similarly, blastocyst production inversely correlates with total precipitation and days >1 mm precipitation ( p < .05). There is a significant decrease in bovine in vitro embryo production efficiency during winter season in our warm-summer Mediterranean climate zone. It remains to be investigated the direct effect of environmental factors on oocyte quality and its impact on in vitro production efficiency. [ABSTRACT FROM AUTHOR]