Comparison of Botu-bov and Tris as freezing extenders of buffalo sperm recovered from epididymal cauda

Abstract

Valuable genetic material can be preserved by the cryopreservation of epididymal sperm. This study evaluated the viability of pre-freezing and post-thawed sperm samples recovered from the epididymal cauda of buffaloes. Epididymides from eight Murrah buffaloes with 18 months of age were used. Semen samples were diluted in two different freezing extenders: Botu-bov (BB) and Tris (TRIS). Immediately after slaughter, both testicles from each animal were collected and transported at 4° C for six hours interval. In laboratory, the removed epididymides were flushed to obtain sperm and the fractions were diluted in both freezing extenders (BB and TRIS). Semen doses were analyzed before and after frozen at -196° C. BB and TRIS pre-freezing results were 38.54±22.33%b and 14.17±12.78%a for total motility (TM), 25.00±16.12a and 9.44±9.11a for progressive motility (PM), 7.21±0.98a and 5.09±2.65a for percentage of rapid cells (RAP), 91.08±12.53b and 63.33±31.47a for velocity of trajectory (VAP), 73.54±20.17b and 49.50±9.11a for linear progressive velocity (VSL), 172.21±24.55a and 116.94±59.48a for curvilinear velocity (VCL), respectively (P < 0.05). BB and TRIS post-thawing results were 42.25±21.50b and 17.62±19.46a for TM, 27.25±24.86a and 18.00±13.68a for PM, 7.35±0.98a and 6.26±1.13a for RAP, 91.42±16.86a and 75.96±13.17a for VAP, 67.96±12.13a and 60.04±10.42a for VSL, 177.54±23.53b and 141.29±24.97a for VCL, respectively (P < 0.05). The sperm recovered from the epididymal cauda, after 6 h storage of epididymides at 5 °C ensures sperm preservation demonstrating that the diluent Botu-bov had higher total motility both pre- and post-freezing when compared with TRIS. Additionally, the sperm frozen with the diluent Botu-bov showed higher values of VSL at post-thawing. These findings may reflect in improvement of conception rates.