The aim of this study was to investigate the effect of the glycogen synthase 1 (GYS1) mutation on performance traits in Noriker draft horse stallions. Individual scores of 32 performance traits were obtained from 169 stallions that took part in the 30-day performance test. The traits were analyzed using a linear model including the GYS1 mutation genotype, the testing year, and age as fixed effects. For the final performance score and 29 traits, no effect of the GYS1 mutation could be found.

We analyzed the relationship between visual ratings of equine conformation and the underlying morphological horse shapes. The rater agreement of eight professional classifiers ranged from 0.30 to 0.55 (correlation). We present a methodological approach, where we associate the individual scores with the horse shapes derived from images, So we can test if the ratings correspond with the observed shape variation. In 58 % of the ratings no association between scores and the phenotypes was found.