Genetic diversity in an indigenous horse breed: implications for mating strategies and the control of future inbreeding.

This study examines the genetic diversity of the Franches-Montagnes horse breed in Switzerland between 2003 to 2008, focusing on horses that have produced at least one offspring. It uses pedigree information and molecular markers to find the best breeding practices to maintain variety, and to prevent future inbreeding.

Research Background and Methodology

• The Franches-Montagnes breed of horses, native to Switzerland, was the focus of this study. It has a population of roughly 2500 foals per year, with a stud book that’s been closed since 1998, meaning no cross-breeding has occurred with other breeds since then.
• Using breeding values for 43 separate traits—including conformation, performance, and coat color—the researchers developed a model to evaluate genetic diversity among this horse population from 2003 to 2008. This model, termed the Best Linear Unbiased Prediction (BLUP) multiple trait animal model, only included horses that have at least one offspring in this time span.
• They used both pedigree information—data on parentage—and molecular markers, which are locations of a gene or DNA sequence on a chromosome, to conduct their study.

Research Findings

• The team screened various software packages to best combine the BLUP methodology with optimal genetic contribution theory—a method to select breeding pairs that would maintain the most genetic diversity.
• They identified stallions with the highest breeding values and the lowest average relationship to the dam (female parent) population. These stallions hold particular genetic importance as breeding with them likely leads to a selection gain—a genetic improvement in the next generation—and can decrease the future inbreeding level within the breed.

Research Impact

• This study is crucial to the conservation of the Franches-Montagnes horse breed, as its findings help to maintain its genetic diversity and prevent future inbreeding.
• By identifying stallions with high breeding potential and low relatedness to the dam population, the researchers have provided a strategy to maximize the genetic variation, thus maintaining the breed’s health and longevity.
• This research can also act as a model for similar studies among different animals, thereby having a transformative impact on biodiversity and conservation genetics overall.