The study investigates whether high or low body fat in stallions affects the quality of their semen after thawing. It found there was no significant impact.

Research Methodology

• The research involved twenty stallions which were divided into two groups based on their Body Condition Score (BCS): Low BCS (those having BCS below 7, n = 11) and High BCS (those having BCS 7 or above, n = 9).
• Each stallion’s body morphology was thoroughly analyzed. This included parameters like neck scores and circumference, crest neck height, body weight and height, and subcutaneous body fat thickness (SFT) at various body locations including the tail head, withers, shoulders, and retroperitoneal space.
• All stallions underwent a fasted Oral Sugar Test (OST). This assessed their glucose metabolism, relevant because high glucose levels could indicate conditions like equine metabolic syndrome which could potentially impact semen quality.
• One semen sample from each stallion was frozen using a commercial egg yolk-based extender. Post-thaw semen quality was then assessed in terms of sperm motility, plasma membrane integrity, mitochondrial membrane potential, hydrogen peroxide and intracellular superoxide production, and lipid peroxidation.

Research Findings

• High-BCS stallions had larger neck circumferences at 25% and 50% of the neck length in comparison to low-BCS stallions. However, there was no significant difference in neck crest height between the two groups.
• High-BCS stallions showed greater SFT at the tail head than the low-BCS ones. But there was no observable difference between the two groups’ SFT at the shoulders and withers.
• All stallions, regardless of their BCS, had resting blood glucose levels below the threshold for equine metabolic syndrome. There were also no significant differences noted between the two groups with respect to resting glucose concentrations or OST peaks, recorded at 30 and 60 minutes after the test began.
• Interestingly, the research found no significant differences in any of the assessed semen parameters between the two groups. This indicates that a stallion’s BCS, whether high or low, doesn’t affect the post-thaw semen parameters if OST findings are within normal limits.

Conclusion

• The findings conclude that stallions’ high or low BCS in the presence of normal blood glucose levels (as indicated by the OST) is not associated with the quality of post-thaw semen parameters, suggesting that body fat levels don’t impact stallion fertility in these conditions.