Table 2. Sperm DNA fragmentation evaluation outcome.
| Spermatozoa with Intact DNA (%) |
Freeze-dried spermatozoa with fragmented DNA (%) |
|||
|---|---|---|---|---|
| Fresh | Freeze-dried | SSBs | DSBs | |
| Ram #1 | 95.7 | 3.8 * | 95.9 | 0.3 |
| Ram #2 | 95.7 | 28.0 * | 70.0 | 2.0 |
| Ram #3 | 95.4 | 2.8 * | 92.6 | 4.6 |
| Ram #4 | 93.7 | 5.0 * | 93.0 | 2.0 |
DNA fragmentation levels in four rams in fresh and freeze-dried sperm samples. Freeze-dried spermatozoa were evaluated for SSBs and DSBs by comet assay based on indication of the existence of SSBs during the Sperm Chromatin Dispersion (SCD) test. No such SSBs indication was noted in the fresh samples when evaluated only by SCD test, suggesting a level of < 10% of SSBs that would not be visible in comet assay. Comet assay values for the fresh samples are thus based on SSBs and DSBs combined. Values of spermatozoa with intact DNA differed significantly between fresh and freeze-dried samples within each ram. All values are based on the evaluation of 300 spermatozoa. Asterisks (*) indicate a significant difference between mean intact DNA values within each row at P < 0.0001.