Quality and fertilizing ability in vivo of sex-sorted stallion spermatozoa.

This study examines the quality and fertilizing capabilities of stallion sperm after being sex-sorted. The study found a decrease in motility but no impact on sperm viability and mitochondrial function post-sorting, and the sorted sperm was still able to fertilize.

Research Method

• The researchers collected ejaculates from four stallions and sorted them using a MoFlo SX flow cytometer/sperm sorter.
• Prior to and following the sorting process, the spermatozoa were evaluated for their motility using Computer Assisted Sperm Analysis.
• The researchers also tested the spermatozoa for viability using SYBR 14-propidium iodide, mitochondrial function using JC-1, and acrosomal status using fluorescein isothiocyanate Pisum sativum agglutinin conjugated.
• A fertility trial was conducted on four mares across seven oestrus cycles by hysteroscopically inseminating them with 5 x 10(6) X-bearing spermatozoa.

Key Findings

• Following sorting, all aspects of sperm motility significantly reduced.
• However, the sorting process did not affect the viability of the sperm and the percentage of spermatozoa with functional mitochondria.
• The percentage of reacted spermatozoa was higher for non-sorted than sorted spermatozoa.
• Following low dose hysteroscopic insemination, the pregnancy rate was 28.6% (2 out of 7).
• Only one of the pregnancies was carried to term, resulting in the birth of a healthy filly.

Conclusion

• Despite the reduction in sperm motility, the sorting process did not degrade the stallion sperm’s viability and mitochondrial activity post-thaw.
• Furthermore, the sorted spermatozoa retained their ability to fertilize in vivo.