Two new important scientific papers on the Thoroughbred
Two really important scientific papers were published today (at least I think they are!).
The first was a paper written by Matthew Binns to do with inbreeding in the thoroughbred. He and his team found (unsurprisingly) that the thoroughbred has increased in inbreeding coefficient in the last 40 years, and even more so since the advent of big stallion books. The papers is really quite eye opening as it outlines the rate of inbreeding and how with the advent of big books, the rate has increased exponentially. The Thoroughbred is an inbred horse as it is, and of course increased inbreeding has been found to have a negative effect on overall population fitness. Binns made no assertions what the level of inbreeding may cause. I am sure that someone will grab on this paper and say that this is the reason we are having more breakdowns in thoroughbreds, or some other theory, but the paper doesn't make that assertion. It actually states that we don't have the data to support something like that at this time.
Importantly, this result is based on inbreeding coefficients determined from the genetic variation present at the DNA level in these horses and not from coefficients calculated on the basis of written pedigrees. We can't see how more inbred horses are becoming just looking at the pedigree page. This paper can be found here
The second paper is on OCD's in thoroughbreds. The discuss the finding of a QTL, or location on the genome, on Chromosome 3 that may have SNP's (changes in the gene code) associated with prevalence of OCD's in thoroughbreds. They do say that their findings need to be independently verified by another source. This is the first paper I have seen on OCD's in thoroughbreds and its genetic cause (there have been papers on other breeds). This paper can be found here
It is going to be really interesting to see how the industry at large reacts when geneticists start finding the variants that cause diseases like OCD's. Are breeders going to make an effort to select away from these types of things (presuming in doing so they don't also select away from speed!)