Genetic correlations between performance traits and radiographic findings in the limbs of German Warmblood riding horses.

The research investigates the genetic correlations between performance traits and particular radiographic findings in German Warmblood riding horses by using results from mare performance tests and auction inspections. Findings suggest that the selection of horses based on the radiological health of their limbs could improve the genetic composition of future performance characteristics in young Warmblood riding horses.

Objective of the research

• The research aimed at studying the genetic correlations between performance traits, such as gaits under rider, rideability, free-jumping ability and character, and radiographic findings in the limbs of German Warmblood horses used for riding. The researchers analyzed these correlations to improve the process of horse selection for breeding and by doing so, enhance the genetic improvement of the performance of young Warmblood riding horses.

Research methods

• The researchers utilized the results from mare performance tests in the field, at station, and from auction inspections. These tests were held between 1995 to 2004. The performance tests evaluated the horses on a scale from 0 to 10 on several traits including gaits under the rider (walk, trot, canter), rideability, free-jumping ability and character.
• The researchers additionally used radiography results of 5,102 Hanoverian Warmblood horses. This involved the investigation of genetic correlations between performance traits and particular radiographic findings such as osseous fragments in fetlock and hock joints, deforming arthropathy in hock joints, and distinct radiographic indications in the navicular bones.
• Genetic parameters were estimated multivariately in linear animal models with Restricted Maximum Likelihood method (REML) using the information on the horses radiographed and their contemporaries (n = 18,609).

Results and conclusions

• The research found that the heritability of performance traits ranged between 0.14 and 0.61, and the heritability of radiographic findings varied between 0.14 and 0.33. This indicates statistical substantiality and relevance in the correlation between these traits and findings.
• The additive genetic correlations between corresponding performance traits were quite high, which implies that the genetic correlations between performance traits could be strong.
• The genetic correlations between performance and radiography results were mostly close to zero, meaning that the radiographic results in the horses’ limbs didn’t have a strong influence on their performance traits.
• The study also found evidence of negative additive genetic correlations for certain pairs of traits and radiographic findings. This indicates that a higher performance in a certain trait could be linked to the predisposition of certain radiographic findings in a horse’s limb, or vice versa.
• These findings suggest that selection of horses based on the radiological health of their limbs could contribute to the genetic improvement of future performance characteristics in Warmblood riding horses.