Use of a colloid to optimize centrifugation in the selection of bovine sperm for IVF

• Published in: Semina. Ciências agrárias : revista cultural e científica da Universidade Estadual de Londrina Vol. 39; no. 4; pp. 1607 - 1616
• Main Authors: Cibele Garcia Moreira Gonçalves, Fábio Gallas Leivas, Daniele Missio, Francielli Weber Santos, Eduardo Brum Schwengber, Natalia Picoli Folchini, Cecilia Urquiza Machado Pavin, Daniela dos Santos Brum
• Format: Journal Article
• Language: English
• Published: Universidade Estadual de Londrina 01-08-2018
• Subjects: Bovine embryo; Cushion centrifugation; In vitro production; Percoll gradients; Sperm recovery
• ISSN: 1676-546X; 1679-0359
• DOI: 10.5433/1679-0359.2018v39n4p1607

This study aimed to evaluate the effect of the force and duration of centrifugation and the impact of cushioned centrifugation on sperm selection by Percoll gradient, on sperm quality and development kinetics of in vitro produced bovine embryos. Two experiments were performed. In Experiment I, a pool of semen was selected by Percoll gradients and the pellet was divided into four groups and distributed in a 2 × 2 factorial, with two forces (2200 × g or 9000 × g) and two durations (1 min or 3 min) of centrifugation. In Experiment II, semen was divided into two groups and selected by Percoll gradient with Cushion Fluid (CF) or without CF (Control) in the second centrifugation. The morphofunctionality, biochemical characteristics and fertilizing capacity of the selected sperms were evaluated. In addition, the development of the resulting bovine embryos was monitored for 48 h post-insemination. Duncan and Chi-square tests (P < 0.05) were used to compare the means. In Experiment I, there was a significant increase in sperm vigor (P < 0.05) after sperm selection in all treatments. The force and duration of centrifugation did not have any effect on sperm motility, vigor, and recovery rate among the different treatments (P > 0.05). In Experiment II, the recovery rate and reactive oxygen species (ROS) production in semen were similar among treatments (P > 0.05) although a higher ROS production was observed in the CF fertilization medium. Total fertilization rate was superior in the CF group (65.4 ± 5.3%) compared to that in Control (39.6 ± 4.9%). However, the normal fertilization and cleavage rate did not differ between the Control (94 ± 6.3% and 58.3 ± 8.3%) and CF (89 ± 7.1% and 75.0 ± 7.3%) groups. The reduction in the force and duration of centrifugation did not decrease the sperm recovery during selection by the Percoll gradient and the use of CF in the second centrifugation did not affect the normal fertilization and development of bovine IVF embryos up to 48 h.