COMPARATIVE EFFICIENCY OF TWO FREEZING EXTENDERS FOR BOVINE SEMEN BASED ON SPERM MOTILITY AND MEMBRANE INTEGRITY.

A. M. CRESPILHO, F. O. PAPA, K. ALBERTI, E. R. SIQUEIRA FILHO, A. MARTINS JR, J. L. C. NOVAES, J. A. DELL'AQUA

Abstract


The quality of the seminal samples has an important role in the determination of the indexes of fertility in artificial insemination programs. In that sense, the aim of the study was to compare the efficacy of 2 extenders for cryopreservation of bull semen in relation to the motility patterns post-thaw evaluated by computer-assisted sperm analysis (CASA), the integrity of plasmatic membrane (IMP) and viability to the fast term-resistance test (TTR)roportionate for each one of the freezing methodology. For the study 10 bulls of the Nelore breed were used, obtaining two ejaculated of each animal. Ejaculates were then splited in two batches, submitted to cryopreservation with the extenders Botu-Bov® (Challenge group) and Tris-egg yolk-fructose (Control group). The data were analyzed by the software Grafpad Instat 5.0, comparing the averages obtained through the ?test T of Student and ?test T with different variances (p<0,05). Among the motional variables generated by the CASA technique, significant differences were observed (p<0,05) for progressive motility (MP), amplitude of lateral head displacement (ALH), beat-cross frequency (BCF), straightness(STR) and linearity (LIN) among the two groups. Influence of the extenders was not observed concerning IMP and resistance to TTR. In conclusion, the present study indicates that the spermatozoa freezing with the Botu-Bov® extender presented greater linearity in relation to the control group, indicating a higher post-thaw viability.
KEY WORDS: Bovine semen. Freezing. Extender. Sperm motility.



DOI: http://dx.doi.org/10.15361/2175-0106.2006v22n3p229-235