Potential role of maternal lineage in the thoroughbred breeding strategy.

This research investigates the heritable factors that contribute to the athletic ability of thoroughbred horses, focusing specifically on the role of the maternal lineage. The study found evidence to suggest that the maternal line has a significantly larger effect on a horse’s racing performance than the paternal line.

Research Methodology

• For this study, data was analyzed from 675 Australia thoroughbreds and their career race performances. The measure of performance used was prize money per start, gathered from the Bloodhound database.
• The performance of each horse was divided into two categories: poor and elite athletic achievement.
• The 675 foals were further separated into four groups based on their parents’ performance. These groupings were: elite dams and elite sires; elite dams and poor sires; poor dams and elite sires; and poor dams and poor sires.
• The researchers compared the performance of foals between these four groupings.

Research Findings

• Results showed a notable difference in heritability of performance from dams (mothers) to foals versus that from sires (fathers) to foals. The study found that race performance has a much higher heritability from dams to foals (r = 0.141) compared to sires to foals (r = 0.035).
• This difference was found to be statistically significant, suggesting that the athletic ability of thoroughbreds is more likely to be inherited from the maternal lineage.
• Additionally, the researchers examined the impact of the dams’ and sires’ child-bearing age on the ratio of elite foals. They discovered a significant correlation between the number of elite offspring and the dams’ child-bearing age.
• Findings showed that the ratio of elite offspring reached a peak when dams were between 8 and 11 years of age.

Conclusion and Implications

• The findings of this study suggest that the maternal lineage plays an essential role in the breeding of high-performance thoroughbreds.
• This highlights the potential importance of maternal lineage in thoroughbred breeding strategies, which present breeders with new considerations for optimising the athletic performance of their horses.