Berglund, Paulina
- Institutionen för husdjurens biovetenskaper, Sveriges lantbruksuniversitet
Sammanfattning
Most horses used for harness racing in Sweden are Swedish Standardbred trotters (SB), but there is also a local breed, the Swedish-Norwegian Coldblooded trotters (CB) that race in separate races and are classified as endangered. Up to now, the two breeding programmes have mainly been focused on improving racing performance. This thesis aimed to study the genetic background of new traits, and the possibility to include them in the genetic evaluation of SB and CB. More specifically, Paper I aimed to study whether racing time could be treated as genetically distinct traits over short-, medium-, and long-distance races in CB. The aim was also to study reranking among top-ranked sires and their relationship to the rest of the population, to evaluate if distance-specific performance could promote the use of stallions that are less related to the population, and to control the high inbreeding rate in CB. The results showed that racing time can be treated as one trait over all distances. Some re-ranking based on breeding values for stallions was seen across the distances. Still, the relationship between stallions was close to half-siblings, and their relationship to the rest of the population was similar for the top-ranked stallions in all distances. In Papers II–IV, two traits reflecting the trotters’ ability to race barefoot were analysed in terms of their genetic background, correlation to performance, and impact on the career length. Racing barefoot has previously been linked to improved racing speed in SB, but not all trotters have hooves that tolerate racing barefoot. Two traits, proportion of barefoot races and barefoot status, were defined for SB and CB, where low to moderate heritability was estimated, and a favourable genetic correlation to performance was found. For both breeds, the results showed that the higher the proportion of barefoot races as a young horse, the shorter the career length. In summary, a trait reflecting the ability to race barefoot seems feasible to include in the genetic evaluation. However, the possible link between a higher proportion of barefoot races at a young age and reduced career length needs to be considered.
Nyckelord
Swedish Standardbred trotter; Swedish-Norwegian Coldblooded trotter; harness racing; performance; novel traits; barefoot racing; inbreeding; breeding programme; heritability; career length
Publicerad i
Acta Universitatis Agriculturae Sueciae
2025, nummer: 2025:58
Utgivare: Swedish University of Agricultural Sciences
SLU författare
UKÄ forskningsämne
Medicinsk biovetenskap
Genetik och genomik
Publikationens identifierare
- DOI: https://doi.org/10.54612/a.7a7foim341
- ISBN: 978-91-8124-042-9
- eISBN: 978-91-8124-088-7
Permanent länk till denna sida (URI)
https://res.slu.se/id/publ/142459