There's been a lot of excitement about equine genomic research over the past couple years, but horse buyers and breeders are still waiting for practical performance applications. The good news is that a team of French researchers might be hot on the trail to genomic evaluation of performance--even if that trail seems slow and winding--one researcher said at a recent research conference.
"This is the first effort at developing a genomic performance evaluation in horses," said Anne Ricard, PhD, a genetics researcher at the French National Institute for Agricultural Research (INRA) in Joay-en-Josas, France. Presented to the public at the 2012 French Equine Research Day held March 1 in Paris, Ricard's research was met with positive criticism from fellow equine and agricultural researchers. Although not yet ready to be used in the horse industry, the project could result in practical applications in the near future.
"There is a lot of potential for this genomic evaluation to surpass the classic genetic system of estimated breeding values," she said. "I have already detected several paths for improvement that could lead us to that point."
Inspired by the results of a genomic performance evaluation in dairy cattle, Ricard and colleagues investigated 908 French sport horses, primarily stallions, using a 54,602 code DNA analysis chip. The group included several families of two or three generations as well as subgroups of half-brothers, which gave the researchers a better opportunity to study genetic performance links, she said.
The researchers deigned a complex mathematical formula for developing a reliable performance indicator based on varying levels of coefficients for certain genetic analysis values. They also calculated data from the performance of parents, siblings, and offspring--called "pseudo-performance"--into the formula, weighted according to proximity of the relationship with the horse being evaluated, according to Ricard.
While the study's results showed some reliability compared to nongenomic standard performance indicators based on performance points and pedigree, they are not yet perfected, Ricard said. "The main problem was that the results pointed out the difference in the breeds more than the difference in performance," she said, specifying that in particular, the Anglo-Arab breed (half Thoroughbred, half Arabian) was clustered together in the analytical graph. "We need to develop a system that will reveal performance levels independent of breed, but we're not there yet."
Even so, Ricard is optimistic, she explained. Her optimism is backed by fellow equine geneticists, including Laurent Schibler, head of the INRA Integrative Biology and Genetics research team. "Despite a non-optimal study design, the system works just as well as the performance indicators we use today," said Schibler. "The use of genomics on a large scale will undoubtedly improve its accuracy and bring new opportunities to the horse breeding industry. Instead of waiting for more sophisticated statistical methods, we should promote horse genomics right now. The time has come for strategic decisions."
Research is ongoing, Ricard said, with a new study planned involving stallions that have a genotyped sire, at least three genotyped half-brothers, and significant pseudo-performance data--the latter of which will improve naturally once the researchers start adding performance-level geldings into the genomic study.
Specific areas of expansion for her project currently in the planning stage include evaluations of life expectancy, morphology, and behavior, Ricard said.
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