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

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 20 mg/mL), aspirated into 0.25 mL straws, and equilibrated at 5 °C for 2 h. After equilibration, the straws were frozen in liquid nitrogen vapor and plunged into liquid nitrogen for storage. Frozen straws were thawed individually for 30 s 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 15 mg/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 15 mg/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 15 mg/mL BSA are beneficial additives for freezing Mahabadi goat spermatozoa in Tris-egg yolk diluent.