Effect of low density lipoproteins in extender on freezability and fertility of buffalo (Bubalus bubalis) bull semen

• Published in: Theriogenology Vol. 76; no. 4; pp. 759 - 764
• Main Authors: Akhter, S, Ansari, M.S, Rakha, B.A, Andrabi, S.M.H, Khalid, M, Ullah, N
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.09.2011; [Oxford]: Butterworth-Heinemann; [New York]: Elsevier Science
• Subjects: Animals; Buffalo spermatozoa; buffaloes; Buffaloes - physiology; bulls; Cell Membrane - physiology; Cell Survival - physiology; Chi-Square Distribution; Cryopreservation; Cryopreservation - methods; Cryopreservation - veterinary; Cryoprotecting agent; Cryoprotective Agents - pharmacology; egg yolk; Fertility; Fertility - physiology; Lipoproteins, LDL - pharmacology; low density lipoprotein; Male; nitrogen; plasma membrane; semen; Semen - physiology; Semen Preservation - methods; Semen Preservation - veterinary; sperm motility; Sperm Motility - physiology; spermatozoa; vapors; viability; Buffalo spermatozoa; Cryopreservation; Fertility; Cryoprotecting agent
• ISSN: 0093-691X; 1879-3231
• DOI: 10.1016/j.theriogenology.2011.04.009

This study was designed to determine whether low-density lipoporoteins (LDLs) extracted from egg yolk in extender improve the freezability and fertility of buffalo bull semen. Semen from three Nili-Ravi buffalo bulls was diluted at 37 °C with tris-citric acid extender (50 × 10⁶ motile spermatozoa mL⁻¹) containing LDLs 2.5%, 5%, 10%, and 15% extracted from egg yolk and extender containing 20% egg yolk was kept as control. Diluted semen was cooled to 4 °C in 2 h, equilibrated at 4 °C for 4 h, filled in 0.5 mL French straws, and kept on liquid nitrogen vapors for 10 min. Straws were then plunged and stored in liquid nitrogen (-196 °C). Sperm motility (visually; %), plasma membrane integrity (%; with supravital hypo-osmotic swelling test), and viability (%; with dual staining test using Trypan-blue Giemsa) were assessed at post-dilution, pre-freezing and post-thawing. At post-dilution and pre-freezing, sperm progressive motility, plasma membrane integrity and viability was similar (P > 0.05) in extender containing 10% LDLs or the control. However, at post-thaw the aforementioned parameters were higher (P < 0.05) in extender containing 10% LDLs compared with the control and other experimental extenders. The fertility rate of inseminations performed were higher (P < 0.05) with extender containing 10% LDLs than the control. It was concluded that LDLs (10%) in extender improved the freezability and fertility of buffalo bull spermatozoa.