Epsilon Archive for Student Projects

Abstract

Of all Swedish Warmblood (SWB) foals born between 2014 and 2018 approximately 24% attended foal inspection. At the foal inspections trained judges assess conformation and gait traits by evaluating/subjective scoring five traits and making a linear profiling/description of 15 traits. The linear assessment of foals was implemented in the SWB population in 2014, and this was the first study based on the linear foal data. Similar data from horses attending Young Horse Test (YHT) are used to estimate breeding values. The aim was to estimate genetic parameters for both linear profiling and evaluating traits and to analyse genetic and phenotypic correlations between the different traits. Another aim was to study the correlations between results of linear profiled traits at foal inspections and later results from Young Horse Test (YHT). The data consisted of data from 2881 foals assessed at foal inspections between 2014 and 20181 and data from 4673 three-year-old horses assessed at YHT between 2013 and 2018. An BLUP animal model with the fixed effects of age in days, event and sex were used to analyse the foal data. For the YHT data the animal model included the fixed effects of event and sex. The event was in both models a combination of location and date of the test. Heritabilities estimated for linear traits assessed at foal inspection were found to be gen-erally low for conformation traits, ranging from 0.03 to 0.28, and medium high for the gait traits, ranging from 0.27 to 0.51. Estimated genetic correlations were strong between evalu-ating conformation and gait traits and their corresponding linear traits, ranging between -0.93 and -1.00. The evaluating trait total score had medium to strong genetic correlations with almost all linear traits, ranging from -0.35 to -0.95. This study showed strong genetic correlations between linear traits assessed at foal in-spection and corresponding traits at YHT. For the conformation traits the genetic correla-tions ranged from 0.59 to 0.93, and for the gait traits from 0.71 to 0.92. Results from this study showed that data from foal inspections has potential to be used in future estimation of linear breeding values, due to its moderately high heritabilities and strong genetic correlations to YHT.