In Vitro Induction of the Acrosome Reaction in Frozen Thawed Spermatozoa from Different Cattle Breeds

Abstract

The standard acrosome reaction (AR) in cryopreserved semen doses of dairy and beef cattle breed was analyzed in this study. 18 frozen semen doses from 6 bulls (3 semen samples per bull) of 3 different cattle breeds (2 Charolais, 2 Holstein, 2 Fleckvieh) were in vitro incubated in three different test media (Heparin, BSA, or a Heparin-BSA system), using TALP medium, to induce in vitro acrosome reaction (AR). The percentage of acrosome reacted spermatozoa was evaluated using the Spermac dichromatic stain, at four different moment (0, 30, 60 or 120 min.). At all time-points, the samples incubated with Heparin-BSA system showed a significant (P<0.05) higher percentage of acrosome-reacted spermatozoa as compared to the samples supplemented with Heparin or BSA alone, while the control media (without supplementation) showed the lowest results. A signii¬cant ini¬‚uence (P<0.05) of cattle breed on the dynamics of the in vitro induced AR was also observed. In our study, the response pattern of in vitro induced AR depended on the culture media, incubation time and nonetheless cattle breed. In consequence, these factors must be taken into consideration when assessing the sperm acrosome reaction in bulls. Â