Comparison of different cryoprotective agents on swamp buffalo semen cryopreservation

Present study aimed to determine the effectiveness of dimethylformamide (DMF) as cryoprotective agent (CPA) by determining its optimum concentration in Tris Eggyolk (TEY) extender on the quality of post-thaw swamp buffalo semen. Only ejaculates having > 60% sperm motility were divided into eight s tubes. Four tubes were diluted in TEY with 4, 5, 6, 7% of glycerol and four other tubes were diluted in TEY with 4, 5, 6, 7% of DMF. Diluted semen then packed into mini s traw (0 . 25 m L ), equilibrated at 4 °C for 4 hours and fr eezed at 8 cm above liquid nitrogen vapour for 10 minutes and then stored at liquid  nitrogen container . After 24 hours of storage, straws were thawed at 37 °C for 30 seconds. The result showed that sperm motility after equilibration tend to be the same at all four glycerol concentrations, whereas the decrease in motility was highest in extenders with a DMF concentration of 7% (P <0.05) . P ost - thaw sperm motility and recovery rate in TEY extender containing 5% DMF or 7% glycerol were highest (P<0.05) than other glycerol or DMF concentration. Sperm viability and membrane integrity did not differ among TEY containing 6% or 7% glycerol, both  were higher (P<0.05) than 4% or 5% glycerol . Viab i lity and membrane integrity of sperm in 5% DMF was superior (P<0.05) to 4%, 6% or 7%. Th is research concluded that 5% DMF or 7% glycerol was considered to be the most suitable CPAs for swamp buffalo semen cryopreservation.