Butylated hydroxytoluene inclusion in semen extender improves the post-thawed semen quality of Nili-Ravi buffalo (Bubalus bubalis)

Abstract The study was carried out to evaluate the potential impact of butylated hydroxytoluene (BHT) on the frozen–thawed semen quality of Nili-Ravi buffalo bulls. Ejaculated bull semen was extended in a Tris–citrate egg yolk extender containing various concentrations of BHT (0.5, 1.0, 2.0 and 3.0 mM). Semen was frozen at −196 °C using 50 × 10 6 spermatozoa per 0.5 mL straws. Five straws from each treatment were thawed to assess the semen quality in terms of sperm motility, viability, plasma membrane integrity and acrosomal integrity. Post-thawed sperm motility was determined using a phase-contrast microscope. Viability, plasma membrane integrity and acrosomal integrity were evaluated by the supravital staining, hypo-osmotic swelling test and normal acrosomal reaction, respectively. The highest ( P P