SUMMARYThe effects of equilibration times (E1, 2 h; E2, 4 h; E3, 6 h), freezing rates (FR1, manual, 5 cm above liquid nitrogen (LN 2 ) for 10 min, plunging in LN 2 ; FR2, programmable ultra-fast, holding at +4°C for 2 min, from 4 to À10°C at À10°C/min, from À10 to À20°C at À15°C/min, from À20 to À120°C at À60°C/min, holding at À120°C for 30 sec, plunging in LN 2 ), and thawing rates (T1, 37°C for 30 sec; T2, 50°C for 15 sec; T3, 70°C for 7 sec) were evaluated on quality of buffalo bull spermatozoa. Progressive motility (%), rapid velocity (%), average path velocity (VAP, lm/s), straight line velocity (VSL, lm/s), and mitochondrial transmembrane potential (%) were higher (p < 0.05) with E2, FR2, and T3 compared to other groups. Sperm curved line velocity (VCL, lm/s) was higher (p < 0.05) with E2 and FR2 compared to other groups. Sperm straightness (%) and linearity (LIN, %) were higher (p < 0.05) with E2 compared to other groups. Sperm LIN was affected (p < 0.05) with T3 compared to other groups. Supravital-plasma membrane integrity (%), viability and acrosome integrity (%) of spermatozoa were higher (p < 0.05) with E2 and FR2 compared to other groups. Sperm DNA integrity (%) was higher (p < 0.05) with FR2 and T1 compared to other groups. We concluded that inclusion of 4 h-equilibration time, programmable ultra-fast freezing rate, and rapid thawing at 70°C for 7 sec in cryopreservation protocol improves the post-thaw quality of buffalo bull spermatozoa.