SELECTION OF BOVINE SPERMS FROM FROZEN-THAWED SEMEN - COMPARISON OF 2 METHODS

The evaluation of methods for gamete selection is very important for in vitro fertilization (IVF). Regarding the male gamete, a population of viable, motile and normal spermatozoa free from seminal plasma contaminants must be selected. The objective of this study was to compare two sperm selection methods: repeated washing-centrifugation (LC) and migration-sedimentation (MS). Frozen-thawed semen was used for all assays (n = 8). in aliquots, simultaneously for each technique. The basic medium utilized was described by Brackett and Oliphant, 1975 (BO). After each method, sperms were assessed through the triple staining technique. Results obtained show that there are statistically significant differences between MS and LC regarding motility: 68.3% vs 46.7% (p < 0.05); viability: 74.6% vs 54.0% (p < 0.05); functional integrity: 67.8% vs 52.5% (p < 0.05), and normal morphology: 98.5% vs 86.5% (p < 0.05%). These results show that MS optimizes the selection of sperm cells.