PROLINE AND GLYCINE BETAINE IN A DILUENT FOR FREEZING CANINE SPERMATOZOA

An attempt to improve the post-thawing quality of dog semen was made, using proline and glycine betaine in three different concentrations. T hese amino acids, used in combination and individually, showed cryopro tective properties when they were added to a ram semen extender, and t his study was carried out to determine whether these compounds could a lso be effective for frozen canine sperm. In this study, semen from 13 dogs was pooled and frozen in a Tris-fructose-citric acid extender co ntaining various concentrations of proline and glycine betaine, both a lone or in combination. The following parameters were evaluated post t hawing as indicators of semen quality: progressive motility, live:dead ratio and acrosomal integrity. Analysis of variance at 0, 0.5, 1, 2 a nd 4 h post-thaw indicated that proline, in all the evaluated concentr ations, exerts a beneficial effect on the post-thaw canine spermatozoa motility and longevity, as well as on the acrosomal integrity. Glycin e betaine alone or combined with proline, did not show any difference compared with the control samples for any of the concentrations used.