Heritability of foot conformation and its relationship to sports performance in a Dutch Warmblood horse population.

The research paper delves into the investigation of heredity factors concerning foot conformation in Dutch Warmblood horses and draws a connection to their sports performance. The researchers found moderate heritability for foot traits, and a weak negative correlation between uneven feet and performance. The paper ends by suggesting that selection can reduce uneven feet prevalence without hurting sports performance.

Methods

• The researchers amassed data from the Royal Dutch Warmblood Studbook, which had information on 44,840 horses, and the Royal Dutch Equestrian Sports Federation, that had records of 33,459 dressage horses and 30,474 showjumping horses.
• By linking the two databases using the unique numbers of each registered horse, the researchers were able to estimate heritabilities, as well as genetic and phenotypic correlations, by examining the jury scores at studbook admission and the corresponding sports performance scores between 1990 and 2002.

Results

• The researchers noticed that unevenly formed feet were prevalent in an average of 53% of horses.
• Despite this, the heritability estimates for foot conformation traits were only moderate, ranging from 0.16 for heel height to 0.27 for hoof shape.
• Furthermore, the correlation between uneven feet and sports performance was found to be negative but slight, being -0.09 with dressage and -0.12 with showjumping.

Conclusions

• The researchers concluded that selection breeding could reduce the predisposition for uneven feet.
• However, the paper also argued that the increased prevalence of uneven feet cannot be directly linked with selection for better sports performance or a higher conformation grade due to weak correlations.
• A caution was also issued if uneven feet came as a result of disproportionate relationships between the horse’s height at the withers and neck length, due to potential development of uneven feet if selection was based on conformation grade.
• In summary, the researchers concluded that limb conformation has a moderate genetic relationship to the conformation grade, and foot conformation traits maintain a genetic connection to performance in sports. Therefore, selecting for reduction of uneven feet can occur without limiting advancements in sports performance.