Evaluation of sperm longevity in refrigerated Buffalo (Bubalus bubalis) semen at 5 oC

Abstract

The semen of 11 buffalo bulls, Murrah, aged from 5 to 6 years, were collected by artificial vagina and submitted physical and morphological analysis of the characteristics of the semen. The objective of the experiment was to test, in vitro, the efficacy of four different extensors (Control -TRIS with 10% LDL- and the same extender at concentrations of 0.5, 1 and 2% of soy lecithin) on the sperm longevity of buffaloes in the refrigeration process at 5 °C for 1, 24, 48, 72, 96 and 120 hours. After collection, each ejaculate was fractionated in 4 aliquots to obtain 50×106 SPTZ/mL, packed in 0.5 mL vats, refrigerated for 4 hours, obtaining a cooling curve of 0.25o C/min. The reeds were kept refrigerated at 5° C and sequentially evaluated, the contents reheated at 37° C/30 seconds prior to the evaluation of sperm motility (total and progressive) using the computerized system. Samples were taken for evaluation by the hypo-osmotic test (HOST) at times 1, 24, 48 and 72 hours. For the statistical analysis, the STATA 12.0 package was used, and the values obtained were submitted to the Friedman test (P < 0.05). Progressive spermatozoa and plasma membrane integrity were higher (P < 0.05) in the TRIS extender with 10% LDL plus 0.5% soybean lecithin (67.2% and 67.9%, respectively) in the refrigeration process for 48 hours. In conclusion, a comparative evaluation of the sperm parameters revealed that the TRIS extender with 10% LDL plus 0.5% soy lecithin can be effectively used in the preservation of refrigerated buffalo semen in AI and IATF for up to 48 hours.