Genetic/Genomic Testing and OCD

KWPN-NAAs I have gotten more interested in sport horse breeding I have started to read up on all sorts of related topics from learning about different registries to spiraling into a black hole tracking a horses bloodlines. Luna is registered KWPN/ Dutch WB. As such I have started trying to understand the different predicates available to KWPN mares.

It is different for all of the studbooks but for KWPN there are different predicates/status for mares. The predicates that a mare is eligible for are outlined on the registry’s website but for a quick rundown:

  • Ster – A horse with above average conformation/movement/ jumping
  • Keur – A mare that is above Ster with quality and has completed an IBOP performance test or sport requirements
  • PROK and/or D-OC – A horse that has passed extensive radiographs or DNA testing
  • IBOP/ Sport – A horse that has passed a riding test or sport performance
  • Elite – A Keur mare that has also passed PROK or D-OC requirments

Generally a horse would be inspected as a 3yo to go from the foalbook (vb) to the studbook (stb). At this time they would also be inspected for Ster or Keur eligibility. At the end of the day whether Luna does well or not or is even presented at keurings does not mean she is or isn’t a quality horse. Primarily I am just excited for our future together in the Jumpers.

dsc_0186-edit.jpgYesterday I found out that Luna passed the D-OC DNA test from KWPN and now has the D-OC predicate. This is essentially a test to determine the heritability or likely hood of a horse to pass OC to its offspring. Here is an excerpt from the KWPN website regarding the D-OC testing.

What is the outcome of the DNA-test?
The outcome of the test DNA will be a genomic breeding value for OC (GFW OC). This value indicates the position of the horse relative to the current KWPN population. On average, 70% of the population of breeding values comes between 96 and 104. Scores a horse more than 104 then it may be expected that the horse inherits less OC to its offspring. Horses scoring 95 or below are expected to contribute negative for OC inheritance.

I personally remain a bit skeptical of the test due to personal experience though I do know that there are external factors impacting a horse developing OCD. That said I figured that as Luna will not be 2yo by the time that the PROK examination is discontinued as a step towards Elite I might as well go for it and see what happened. Who knows if she will even achieve the other requirements anyways.

Is there anyone else that’s involved or interested in breeding that knows of other registries with similar developing DNA testing protocols? I find it all very interesting but at the end of the day I don’t think that there will be a total eradication of the presence of OCDs and will wait to see how accurate this genetic/genomic testing ends up being. I guess if you don’t make steps in the right direction with research to understand the cause/problem there will never be progress though. Thoughts?


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  1. Interesting! Kinda cool they’re taking a stance on OCD, though I don’t really understand what the scoring means. Good for the registry to try to work towards that.

    I have to say, though. Everytime someone mentions a “keuring”, I immediately think coffee machine. Haha

    Congrats to Luna!

  2. I admit to knowing next to nothing about sport horse breeding, but I found your post about it interesting, especially the genetic testing part. Looking forward to more posts like this!

  3. Super interesting. Kind of reminds me of AQHA and HYPP status. Every stallion now has to have a 5 panel test in order for their foals to be eligible for registration. It’s interesting that they do it for mares as well, I think that’s smart!

    1. If my understanding is correct stallions have to get the DNA test and radiographs. It’s interesting for sure. For mares born into the foal book it isn’t required to get into the studbook unless you want to / as a step to elite. I believe mares from outside books would need to get rads still to be entered into the main book.

  4. Very interesting! I never knew this. I think it’s a good thing, but you’re right – there are external factors that can contribute.

  5. Interesting stuff. I thought OCDs were primarily caused by external factors and not hereditary. I’ve heard from breeders that the rule of thumb is keep the young ones lean and the chance of OCD developing is small. I just recently saw a study done on youngsters that took xrays when they were a few months old, and then again when they were 18 months old. The ones that were kept lean showed OCDs healing/disappearing/not appearing. The ones that were fattened up had a higher percentage of OCDs. Wish I remembered where I saw the study.