Breeding for durable riding horses using competition statistics

• The breeding objectives for Swedish Warmblood horses are aiming for producing horses that have a good conformation and are internationally competitive in dressage and show jumping. It also states that the horses should be durable. The aim of this thesis was to investigate whether it is possible to use existing competition statistics for genetic evaluation of durability and, if so, how this should be done. Number of years in competition (NYC) was used as a measure of durability. Genetic analyses were performed using linear animal models where heritabilities, genetic correlations, and breeding values (EBV) were estimated. It was concluded that birth year and age at first placing should be included as fixed effects in the model. Age at first placing is, to a great extent, reflecting the talent of the horse and since information about durability is desired, the suggestion is to adjust for the age effect in the analyses of NYC. Three different datasets were tested when heritabilities and EBVs were estimated. The datasets varied based on sex and birth year of the included horses. Heritabilities for NYC were in the same range for all three datasets (total 0.06-0.07; show jumping 0.08-0.12; dressage 0.07-0.08; eventing 0.04-0.08) and there were high correlations between EBVs within the same discipline for the different datasets. The genetic correlations between total NYC and performance traits from competition and Riding Horse Quality Test (RHQT) were higher for jumping traits (0.65-0.69) than for dressage (0.27-0.40) indicating that there are connections between level of performance and NYC. The conclusions of the results were that it is recommended to estimate EBVs for NYC for stallions with a linear animal model and that they should be published for each discipline separately. Besides the genetic analyses, the study showed that horses with successful results from more than one discipline at an early age had significantly more years in competition compared to the other horses. This indicates that an all-round training of young horses has a positive effect on the durability of the horse.

Ämnesord

LANTBRUKSVETENSKAPER  -- Husdjursvetenskap -- Husdjursvetenskap (hsv//swe)

AGRICULTURAL SCIENCES  -- Animal and Dairy Sience -- Animal and Dairy Science. (hsv//eng)

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