'Semen dilution effect' on sperm variables and conception rate in buffalo.

Area of Science:

• Reproductive Biology
• Animal Science
• Cryopreservation Technology

Background:

• Buffalo semen cryopreservation faces challenges due to dilution effects.
• Optimizing extender composition is key to preserving sperm quality post-thaw.
• Understanding extender impact on sperm parameters is vital for artificial insemination success.

Purpose of the Study:

• To evaluate egg yolk (EY), low-density lipoprotein (LDL), and OptiXcell (OC) extenders for minimizing buffalo semen dilution effects.
• To determine optimal sperm concentration per dose for cryopreservation.
• To assess the impact of different extenders and dilutions on post-thaw sperm quality and fertility.

Main Methods:

• Buffalo ejaculates (n=18) were diluted with EY, LDL, or OC extenders to 20, 12, or 2 million sperm/dose.
• Sperm motility, plasma membrane integrity, capacitation, velocity, head displacement, and mitochondrial activity were analyzed.
• Cryopreserved semen was used to determine conception rates (CR).

Main Results:

• Dilution to 2 million sperm/dose significantly reduced sperm motility, plasma membrane integrity, and increased un-capacitation and mitochondrial superoxide production.
• LDL extender demonstrated superior cryopreservation efficacy compared to OC and EY extenders, especially at lower sperm concentrations.
• Conception rates were unaffected at 20 and 12 million sperm/dose but decreased significantly at 2 million sperm/dose.

Conclusions:

• Buffalo semen dilution to 12 million sperm/dose is acceptable, maintaining most seminal variables and conception rates.
• LDL extender at 2 million sperm/dose offers significant protection against semen dilution effects.
• Optimizing extender choice and sperm concentration is critical for successful buffalo semen cryopreservation and fertility.