Effects of various concentrations of BSA on microscopic and oxidative parameters of Mahabadi goat semen following the freeze–thaw process

Abstract

Artificial insemination has an important role in goat breeding. Semen cryopreservation could provide genetic material from a small number of superior sires to a large number of females. The purpose of the present study was to investigate the effects of bovine serum albumin (BSA) on sperm parameters following the freeze–thaw process. Semen samples diluted with Tris-based extender containing various concentrations of BSA (0, 2.5, 5, 10, 15 and 20mg/mL), aspirated into 0.25mL straws, and equilibrated at 5°C for 2h. After equilibration, the straws were frozen in liquid nitrogen vapor and plunged into liquid nitrogen for storage. Frozen straws were thawed individually for 30s in a water bath (37°C) for microscopic evaluation. Sperm parameters in terms of motility and progressive motility, viability, membrane integrity, acrosome integrity and capacitation status, were assessed. Malondialdehyde (MDA) and glutathione peroxidase (GSH-PX) activity were also evaluated after freeze–thaw process. Freezing extenders supplemented with 10 or 15mg/mL of BSA had higher sperm motility, progressive motility and viability (p<0.05) following the freeze–thaw process. In biochemical assays, the application of 10 or 15mg/mL of BSA produced the lowest level of MDA, compared to the control group (p<0.01). It is concluded that inclusion of 10 or 15mg/mL BSA are beneficial additives for freezing Mahabadi goat spermatozoa in Tris–egg yolk diluent.