Genetic analysis of competition traits in Icelandic Horses

• Main Author: Elsa Albertsdóttir
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Iceland
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.630.3767; http://pub.epsilon.slu.se/1347/1/Albertsd%C3%B2ttir_21.pdf

The aim of this thesis was to explore the basis for including competition traits in the genetic evaluations of the Icelandic horse. This evaluation is currently based on breeding field-test traits. For this purpose knowledge about genetic parameters of the competition traits, and of genetic relationships between competition traits and the breeding field-test traits was required. A data-set including 18 982 records of 3790 horses competing in Iceland and Sweden 1998 – 2004 were analysed using linear animal models. The traits analysed were two different measures of four-gait, five-gait and tölt, and one pace trait. Additionally, new combined traits were formed and analysed in order to describe the competition traits in simpler manner. The estimated heritabilities were low to moderately high (0.18 – 0.35) for all competition traits. The genetic correlations estimated among competition traits (-0.42 – 1.00) were generally strong and favourable with a few exceptions. Genetic relationships were estimated between breeding field-test traits and combined competition traits, along with one original competition trait (pace). The breeding field-test data included 16 401 individual records of Icelandic horses evaluated in 11 countries during