Association of body shape with amount of Arabian genetic contribution in the Lipizzan horse

Abstract

Abstract.Crossbreeding between individuals of different breeds and introgression, the transfer of genes between breeds and/or populations mediated primarily by backcrossing, have been characteristic tools used in the refinement or optimisation of practical horse breeding. In this study we analysed the genetic contribution of the Arabian horse to the gene pool of the Lipizzan horse and its association with the overall type via shape regression analysis in 158 Lipizzan horses from the Austrian federal stud farm of Piber and the Spanish Riding School. Although crossbreeding with Arabian horses took place between 1776 and 1945, we found a significant association between Lipizzan body shape (p < 0.003) and individual coefficients of Arabian gene proportion, which varied from 21 to 29 %. In order to compare and interpret the estimated Lipizzan shape transitions from Iberian type towards the oriental type, we included a sample of 32 Shagya Arabians from the Slovak National stud farm Topol'ćianky. The estimated shape transitions in Lipizzans due to an increasing proportion of Arabian genes are similar to those we observed in the population comparison study of Lipizzan and Shagya Arabian horses. The main morphometric differences due to increasing Arabian genetic contributions in Lipizzans were found in the conformation of head, neck, withers, and legs. Although selection in the Austrian Lipizzan breed favours the Iberian type, Arabian shape characteristics are still present, indicating the segregation of Arabian founder haplotypes in the population. We also demonstrated that techniques of shape analysis are able to differentiate phenotypes associated with the gene pool and can be applied for phenotypic evaluation and prediction in crossbreeding programs.

Genetic Parameters of Linear Type Traits Scored at 30 Months in Italian Heavy Draught Horse

“…The direct measurement of body regions has been widely accounted in horse literature, such as in the Andalusian horse [ 14 ], the Lipizzan [ 26 ] and the Noriker [ 6 ]. Morphometric measurements have received recent improvements by the software for image analysis of individual body pictures, as for the Spanish Arab Horse [ 38 ], and, more recently, for the Lipizzan horse [ 54 , 55 ]. Since the first evaluation system proposed in 1989 for the Dutch Warmblood [ 4 ], many studies have been based on linear scoring system, in which a number of traits are individually scored along a biological scale to evaluate body regions (e.g., in Shetland pony [ 37 ]; in the Italian Haflinger [ 5 ]).…”

High-resolution population structure and runs of homozygosity reveal the genetic architecture of complex traits in the Lipizzan horse

“…The Lipizzan horse breed is globally one of the best-documented horse population, as pedigree records can be traced back to the known founder animals born in the early eighteenth century. The founder population, described in detail by Zechner et al [1], Druml and Sölkner [2] and Druml et al [3], comprises 456 animals, whereas the major part of horses originated from the former imperial stud farm of Lipica founded in the year 1580. Since the First World War the stud book of Lipizzan horses is closed and presently conservation breeding strategies are applied by eleven state stud farms located in nine European countries.…”

“…Comprehensive pedigree data (max. 31 generations, generation equivalent 19.1) were used to estimate inbreeding coefficients and effective population sizes by Zechner et al [1], Sölkner and Druml [2] and Druml et al [3]. Furthermore, microsatellite markers were employed to describe diversity measures, genetic distances and population structure by Achmann et al [4].…”

Digitalization - mainstream in optimizing the solution of breeding problems

“…T. Druml et al [10] differentiated by the methods of geometric morphometry based on image analysis according to the phenotypic traits of Arabian horses of different genetic origin, having come to the conclusion that this method of phenotyping and analysis can be used to identify the main effects of genetic introgression and predict conformation transitions with an increase and decrease in the genetic contribution of other breeds.…”