Variaciones metodológicas en Criopreservación de semen Sexado DE bovinos

Abstract

The objective of this study was to evaluate the effects of 3 different cooling protocols for freezing bovine sexed semen by flow cytometry. It was used two ejaculates of 10 bulls, after collection of semen that was processed for separation of X and Y sperm. After separation by the cytometer, the samples were divided into 3 groups: control (C), the sperm were placed in medium without glycerol and stored at 5°C/90 minutes, group 1 (G1), the sperm were placed in medium without glycerol and stored at 18ºC/90 minutes, group 2 (G2), the sperm were placed in medium with glycerol and stored at 5°C/90 minutes Subsequently the samples were stored in straws and subjected to freezing. After thawing, samples were evaluated following sperm parameters: sperm analysis of the kinetics through a computerized system (CASA), the sperm membrane integrity and mitochondrial potential by epifluorescence microscopy. For statistical analysis it was used ANOVA and Tukey's test where appropriate, with significance level P < 0.05. For the kinetic analysis of sperm was found that the values of linear velocity by G1 (82.3μm/s) were lower as compared to G2 (90.5μm/s) and C (89.7μm/s) and for curvilinear velocity, group C (206.6μm/s) showed values higher than G1 (183.0μm/s) and G2 (194.2μm/s) similar to both. For plasma membrane integrity G2 (34.7%) had significantly lower than C (39.4%) and G1 (41.6%), however mitochondrial function values were higher in group C (62, 6%) compared to G1 (47.5%); and, G2 (51.1%) was similar to both. Based on the results obtained can be conclude that 3 protocols adopted for cooling the freezing of semen sexed cattle showed few variation. Thus further studies are needed to improve the procedure of cryopreservation of bovine sexed semen.