34 A Comparison of International Genetic Evaluations of Show Jumping in Sport Horses

Abstract The breeding of sport horses to compete in show jumping is fast becoming a global industry with the increased use of reproductive technologies, including artificial insemination and embryo transfer, facilitating the dissemination of genetics from elite horses across multiple countries and breeds. Due to this increased level of crossbreeding, there is an increased need for estimate breeding values for sport horse performance that can be compared across breeds and countries. However, the implementation of a cross-breed or across-country genetic evaluations has been limited by the differences in individual breeding programs and genetic evaluations in each studbook. Consequently, the aim of this study was to compare the genetic evaluations for show jumping of sport horse studbooks worldwide. An email was sent to the studbooks included in the World Breeding Federation for Sport Horses Studbook Rankings for show jumping in 2019 to request information on their current breeding programs and genetic evaluations. Twenty-six of the 51 studbooks contacted replied to this request. Only 18 of these studbooks conducted their own genetic evaluations or were part of a larger genetic evaluation in their country of origin. Overall, many differences were identified among the genetic evaluations of each studbook or each country. The definition of show jumping performance differed within each evaluation and the methods and models utilized also differed (Table 1). Despite some stallions and mares being registered in multiple studbooks or having progeny in multiple studbooks, these differences make comparison of estimated breeding values across studbooks difficult. Further transparency and collaboration of sport horse studbooks with organizations such as Interstallion, will be essential to facilitate any future implementation of international genetic evaluations for show jumping performance.