Genetic analysis of different traits in horse breeding by considering radiographic findings -: 2nd communication:: Genetic relations between conformation traits, performance traits and bone diseases

In order to analyse the importance of different traits in horse breeding, genetic parameters were estimated. In this analysis, the radiographic findings, 10548 results of stutbook registration and 1240 mare performance test results were used. To examine the possibility of considering these different traits in a breeding program, genetic correlations among X-ray findings, the traits of the stutbook registration and mare performance tests were estimated. The results of this study can be summarised as follows: Estimated heritabilities for the conformation traits ranged from h(2) = 0.12 to h(2) = 0.42. Genetic correlations between these traits were in general positive and of high magnitude for some traits, indicating the possibility of reducing the number of recorded traits. Heritabilities estimated for the traits recorded on mare performance test varied between h(2) = 0.23 and h(2) = 0.85. The rideability showed the highest genetic correlation to basic gaits, whereas the trait free jumping showed lower correlations to the basic gaits and the rideability. Estimates of genetic correlation between bone diseases and conformation traits were low. Estimates up to r(g) = -0.17 showed a negative tendency. A carefull interpretation of these correlations might be that the evaluation of conformation traits may have a positive influence on reducing the frequency of bone disorders. Bone diseases and the traits of the mare performance test showed no genetic correlations. Apparently, the considered X-ray findings had no negative influence on the performance of the tested mares. The results of this study clearly indicate that the health status can be improved by additional recording of health traits and selection. Data recording and selection should be used in an optimized breeding programme.