Selection of frozen bull spermatozoa for in vitro fertilization Selección de espermatozoides de toro para fecundación in vitro

Abstract

The swim-up and Percoll gradient techniques were evaluated for the selection of frozen bovine spermatozoa to be used on an in vitro fertilization system. The parameters assayed were: concentration, morphology, motility and rate of in vitro fertilization and rate of development. The spermatozoa were from a single bull and the oocytes were aspirated from ovaries obtained at the slaughter house and matured in vitro. Sperm motility increased significantly (p<0.05) from 70%-75% to 90% - 95%. However after sperm selection there was no significant difference between both methods (p>0.05). Sperm concentration after swim-up was 3.33 × 106 sp/ml and with Percoll 16.5 × 106 sp/ml (p<0.01). Samples obtained by both methods showed a decrease in abnormal spermatozoa as compared to controls (17.3% in swim-up; 24.8% in Percoll and 47% in control) (p<0.01). There was a significant difference between both methods only in regards to anomalies of the neck region (3.5% in swim-up and 9.6% in Percoll (p>0.0