The effect of frozen storage on ram sperm DNA integrity

Barker, Theresa-Fina
University of Sydney


Artificial insemination (AI) is broadly used in the sheep industry as a means to propagate elite male genetics. Within the livestock industry, there is growing interest in the role of sperm DNA integrity in sire fertility and the implications of the freeze-thaw process on this trait. As such, this study evaluated the integrity of sperm DNA before and after cryopreservation using two DNA integrity assays; the sperm chromatin dispersion test 6 (HALO) and single-cell gel electrophoresis (COMET), to determine whether frozen storage has a negative impact on ram sperm DNA. Ejaculates (n=9) were collected from mature Merino rams (n=3) and separated into fresh or frozen-thawed treatments for analysis using these two assays. Statistical analysis by one-way ANOVA showed fresh and frozen-thawed sperm did not significantly (P>0.05) differ in DNA integrity measured by any means. These results highlight that cryopreservation of sperm for use in AI does not degrade sperm DNA integrity. The application of this study will facilitate a better understanding of the impact that frozen storage of sperm has on DNA integrity. Subsequent research involving a larger sample size and assessing the role of such samples in fertility outcomes will validate these results.

A thesis was not submitted for this project. This is an option provided for all recipients