R. Bras. Zootec.01/Apr/2007;36(2):387-95.
Relationship between conception rates obtained by using bovine frozen semen and in vitro spermatic evaluation
DOI: 10.1590/S1516-35982007000200016
The objective of this study was to evaluate the relationship between complementary (hiposmotic, thermo-resistance and acrosome reaction tests) and conventional evaluations (physical and morphologic aspects) of bovine frozen/thawed semen and conception rates. Average values for spermatic motility evaluated by thermo-resistance test were of 53.48% (post-thawed), 43.69% (60 minutes), 35.88% (120 minutes) and 33.04% (180 minutes). The percentage of reactive cells observed for the hiposmotic test was 37.89%. Average intensity was observed for post-thawing spermatic motility, positively correlated to hiposmotic test (0.21). However, correlation between motility in the 180 minutes and hiposmotic test was high (0.64). The percentage of cells presenting post-thawing acrosome reaction was 9.85%, which was negative correlated to post-thawing (-0.25) and after three hours of incubation (-0.46) spermatic motility. No correlation was observed for complementary tests and post-thawed motility and the conception rate. No one of the parameters evaluated in this study was individually able to indicate the fertilizing capacity of the frozen/thawed semen.
Keywords: bull; complementary tests; fertility; sex selection