Pedigree Analysis of Warmblood Horses Participating in Competitions for Young Horses.

The research article assesses the genetic diversity and population structure of Warmblood horses used in show jumping. Analyzing the pedigree data of over a thousand horses, it found that modern sport horses come from a small number of quality sires and suggest ongoing monitoring of the inbreeding level.

Population Structure and Genetic Diversity Characterization

• The primary aim of the research was to understand the population structure and assess the genetic diversity of Warmblood horses. These horses are prominently used in the show jumping discipline, a sport testifying the horse’s agility and the rider’s accuracy.
• The population characterization was carried out by analyzing the pedigree data of over a thousand horses that partook in the Polish Championships for Young Horses. In total, the pedigree of the examined animals consisted of 12,863 individuals.

Pedigree Analysis and Inbreeding Coefficient Assessment

• The researchers conducted an analysis of the horses’ pedigree structure along with characterizing the homozygosity, which is the genetic condition of having two identical alleles at a particular locus, and genetic diversity in the population.
• They found that the pedigree’s completeness and depth were substantial enough for a reliable assessment of the genetic diversity in the examined population.
• Albeit the average inbreeding coefficient (a measure of the likelihood that two alleles at any locus in an individual will be identical by descent from the parents) represented an acceptable level at around 1.01%, the researchers noted a disturbing upward trend in the percentage of inbred animals.

Findings and Recommendations

• The results of the study indicated that the modern sport horses descend from a limited number of high-quality sires, a phenomenon known as the bottleneck effect, where the offspring of these sires are intensively used for breeding.
• This caused a larger proportion of genetic variation reduction to be observed in the non-founder generations (those who are not part of the original population).
• Given these changes within the studied population, the researchers recommended the continual monitoring of inbreeding levels in modern sport horses.
• They emphasized that pedigree data should be efficiently utilized in the selection process for mating to safeguard genetic diversity and maintain the health of the horse population.