Hur förselektion av hästar till bedömning och tävling kan hanteras i avelsvärderingen

Sammanfattning: The Swedish Warmblood riding horse is a popular horse for sport in Sweden, and the breeding goal is to produce competitive horses in both show jumping and dressage. The breed has its origin in native Swedish cavalry horses but has been highly influenced by foreign stallions throughout the years. Breeding values are estimated based on the results from young horse field test, which are held for 3- or 4-year old horses, and competition data. The young horse field tests are highly correlated with later performances in competition. The total proportion of horses with own observations to include in the genetic evaluation are slightly under 50 %, and in most cases their pedigrees are known. Pre-selection occurs when parts of the population never is tested at young age or never compete due to an assumed lack of talent. This can led to an underestimation of breeding values, which has been shown in other populations of farm animals. Pre-selection occurs in most horse breeds, but to different degrees. An inclusion of competition- or field teststats has been proven to reduce the effect of pre-selection in other horse breeds. However, the breeding values of Swedish Warmbloods are based upon information from both young horse tests and competition. It can be assumed that this reduce the effect of pre-selection to some extent. It would be interesting to further study of including test status in the genetic evaluation of Swedish Warmblood.