Assessment of sperm DNA fragmentation in stallion (Equus caballus) and donkey (Equus asinus) using the sperm chromatin dispersion test.

This research article is about evaluating the quality of sperm in donkeys, particularly in a breed at risk of extinction, using the sperm chromatin dispersion test initially designed for other animals. It includes the differences in test results between stallions and donkeys.

Objectives of the Study

• The main aim of this study was to evaluate the usefulness of the Sperm Chromatin Dispersion Test (SCD), also known as the sperm Halomax test, in assessing sperm DNA fragmentation (sDF) in an endangered donkey breed.
• The study sought to adapt the four commercial variants of the SCD test, originally designed for boars, bulls, rams, and stallions, for use in donkeys.

Methodology and Findings

• Image analysis was used to compare differences in test results between stallions and donkeys.
• Each of the four variants of the SCD test was used on donkey semen samples to assess their effectiveness.
• The researchers found that only the version of the SCD test initially created for stallions produced consistent and stable results when used on donkey sperm.
• All tests were performed under the same experimental conditions to ensure accurate comparisons.

INDICATORS of Sperm Quality

• The extent of SCD in the test was approximately 20% lower in donkey sperm than in stallion sperm.
• Despite this, the ratio of chromatin sperm dispersion in fragmented and unfragmented nuclei didn’t significantly differ between species, suggesting that similar protein depletion treatment can generate different results in similar cells from different species.
• The findings indicate that sperm chromatin might be organized differently in stallions and donkeys, affecting the reliability of the test in different species.

Implications of the Study

• The findings of this study are crucial in advancing sperm analysis in donkeys, especially for endangered breeds such as the Zamorano-Leonesa.
• The research suggests that the SCD test used for stallions can also be used reliably to assess DNA fragmentation in donkey sperm.
• These results could potentially contribute to breeding and conservation efforts by providing valuable information regarding the quality of sperm in these animals.