Removing seminal plasma improves bovine sperm sex-sorting

Area of Science:

• Reproductive biology
• Animal science
• Sperm sorting technology

Background:

• Bull ejaculates with low sperm concentrations exhibit poor sex-sorting performance.
• The underlying cause, whether low sperm count or high seminal plasma content, remains unclear.

Purpose of the Study:

• Investigate the reasons for poor sex-sorting efficiency in low sperm concentration ejaculates.
• Develop protocols to enhance sperm sex-sorting efficiency in cattle.

Main Methods:

• Conducted experiments varying sperm concentration, seminal plasma levels, and Hoechst 33342 staining parameters.
• Assessed sperm viability, membrane integrity, and sex-sorting rates under different conditions.
• Evaluated the impact of seminal plasma concentration on sperm quality post-cryopreservation.

Main Results:

• Optimal staining involved 160 × 10^6 sperm/mL with 65 μm Hoechst 33342 and no seminal plasma.
• Higher sample concentrations (2.1 × 10^9 sperm/mL) reduced membrane-impaired sperm percentages and improved X sort rates.
• Samples with 0% seminal plasma showed higher live-oriented cell percentages, fewer dead sperm, and better post-thaw motility.

Conclusions:

• Sperm sex-sorting efficiency is primarily influenced by seminal plasma concentration, not the initial sperm concentration.
• Diluting ejaculates to a standard concentration (160 × 10^6 sperm/mL) for staining minimizes seminal plasma interference.
• Reducing seminal plasma content enhances sperm quality and sorting performance, leading to improved cryopreservation outcomes.