Just knowing he had an oc lesion did not turn breeders away from Bretton Woods, but that was before he had sufficient foals to sample. Now that he carries a negative oc index that indicates he is more likely to produce it in his offspring than a stallion with a more positive oc index, we shall see if breeders will use him. Bordeaux also had an oc lesion, but his index indicates that he is not likely to pass it to his foals.
I think the major point the KWPN has tried to make known is that it is far more important to know which individuals PRODUCE oc in their offspring, not so much that they have or don’t have oc themselves. It’s great to have oc free stallions and mares, but what I’m saying is that the registry is focusing on the stallions for these indexes simply because mares can’t have enough foals to give a random sample that is statistically significant to account for the environment vs genetic variables. I’m not saying that the registry doesn’t recognize the importance of the other half of the breeding equation with mares, I’m merely pointing out that the registry can’t give an oc index to mares because the numbers aren’t there in terms of foals to sample. Using oc-free individual mares is something breeders can choose to do. But, no one here can identify whether or not their individual foal’s oc was environmental or genetic. How do you do that with one foal? or six? And btw, not everyone agrees 100% on what is the ideal feed/environment, plus “environment” means everything that is not genetic, which also then includes injury. Even weather potentially. And how could you determine that the spill your foal took in the mud did or did not contribute to it one day having a lesion? The variables are great, so the KWPN focuses on what it can to give breeders meaningful data for breeding decisions. The practice of choosing stallions with a better index is not going to rule out oc, but I’m personally not going to choose a stallion that is more likely to produce oc over a stallion who is less likely to do so. Why gamble with less favorable odds in a venture that is filled with plenty of risk anyway.
Perhaps somebody here with knowledge of statistical methods and the vocabulary to explain it could assist in making what I think is a very simple concept more understandable to folks reading about what the KWPN is doing. I’m probably not that person. I get the feeling folks are confused still about the difference between a horse being oc free and what the index means.
Good morning. As a long-time KWPN breeder, I’ve always appreciated the amount of information this studbook makes available to breeders. In my earlier days of breeding, I can’t tell you how many hours were spent pouring over indices, isolating traits, and weighing one stallion against another. Although I still glance at these indices and take them into consideration, they don’t have the same weight for me as the performance and soundness results of stallion, mare, siblings, and immediate horses in the pedigree. Bretton Woods’s dam is an elite mare, which means she passed the same radiographs requirements as an approved stallion. Johnson, his sire, also passed. Bretton Woods has an approved half brother, Chagall, with clean xrays, and his younger half brother, Gaudi, by Totilas, is being presented to the KWPN in the next cycle–he, too, has clean xrays. Given the depth of his pedigree, the soundness of his family, and his own talent for dressage, the fact that Bretton Woods scored a 96 on the OCD index on the basis of offspring no more than two-years-old, I can’t be too concerned. Also, keep in mind that in the KWPN indices, 100 normally equals the average of the population. A score higher than 100 means the stallion improves the trait; a score less than 100 means he negatively affects it. Again, normally in these indices, the score is not considered significant unless it is 10 or 20 points in either direction from 100, with each 20 point mark being more and more significant. So a 96 is really close to average and fairly insignificant. In this case, the 100 representing the average of the population is the average of 21 or 22 stallions, right? I’m just not sure how much weight we should give these numbers at this point in time. As more stallions are included and more, and older, offspring are examined, this index will be more valuable. Just thoughts.
Thanks Scot, that’s excellent perspective. I’m not certain about the weight of the scores in either direction of 100 however, it seems I read elsewhere that the 96 was considered significant for this index? Time will change these numbers of course, and it’s even possible that over time BW’s index would move closer to 100. So, it is important not to get too hung up on these things and realize that they are meant as indicators, not absolutes and are derived from statistics, not genetic testing.
Speaking for myself, I do say that I will try to avoid the stallions that have been determined to have OCD grade 3 or more… There are enough things that can go wrong when breeding horses, so why stack the odds against you even more? The vast majority of the stallions that I consider for my mares are OCD free and - knock on wood - 98% of the foals I’ve produced have x-rayed perfectly. Why rock the boat? 
[QUOTE=paulamc;7038129]
Hi, there has been a lot of talk about this here in Australia lately
Breeders are saying that stallions like Hotline are well known for passing on OCD or have a positive index for this
Paula mc[/QUOTE]
I have never read anywhere that Hotline passes on OCD. Ugly heads maybe but never OCD. Could you tell me where you have your information from?
Ditto to HickoryHill! And I did breed one of my mares to Hotline and got a filly that passed her vet inspection with flying colors at age 3.
