Effect of supplementation of glutamic acid and aspartic acid in egg yolk tris and egg yolk-citrate-glucose diluents on cryopreservation of Murrah buffalo bull spermatozoa

Abstract

Present study was designed to assess the effect of supplementation of glutamic acid and aspartic acid in egg yolk tris and egg yolk-citrate-glucose diluents on spermatozoa quality of Murrah buffalo bull after equilibration and thawing. Semen was collected from four Murrah buffalo bulls biweekly from each bull with the help of artificial vagina (AV) on dummy animal between 08:00 to 09:00 hours using standard protocol. A total of thirty two ejaculates were taken from four bulls. In fresh ejaculates were pooled and divided into eight equal parts. The two basic diluents used for extending semen were Egg yolk Tris (EYT) and Egg yolk-citrate glucose (EYCG). Glutamic acid and aspartic acid were supplemented in different combinations. Diluted semen was equilibrated and cryopreserved. At two stages viz. after equilibration and after 12 hours of cryopreservation (thawed samples) progressive motility, percent live and percent acrosomal damage of spermatozoa was assessed. Post thaw acrosomal damage was significantly higher (P<0.05) in EYCG than EYT. Supplementation of aspartic acid to EYT and EYCG significantly (P<0.05) decreased the post thaw acrosomal damage as compared to control. Supplementation of glutamic acid to EYT and EYCG significantly (P<0.05) improved all the studied spermatozoa qualities. The addition of both aspartic and glutamic acid together did not produce any additive effect on spermatozoa quality. It can be concluded that tris buffer was a better substitute to citrate buffer and glutamic acid alone may be supplemented to semen extender to improve the spermatozoa quality after equilibration and thawing.