Updated PROK requirements

March 6, 2024

Updated PROK requirements


The KWPN has established updated PROK requirements

The main objective of the KWPN is to breed horses that can perform at the highest level in the sport. Ensuring the correct selection based on health characteristics is important to guarantee its distinctive character as a studbook. For this reason, the approved stallions themselves must also be sufficiently healthy, so that breeders can make better choices and breed more sustainable horses.

During the coming Annual General Meeting (AGM), the KWPN manager of Breeding Operations, Ralph van Venrooij, will give a presentation on this topic. You’ll have plenty of opportunity to ask questions too. Go to this page to learn more on the AGM! It will take place from March 14-16 in Ocala, Florida. 

In the summer of 2023, the PROK requirement was reintroduced within the stallion selection process. At the same time, the General Board established a Veterinary Advisory Committee to reassess the current PROK requirement. This group of renowned veterinarians and radiologists has formulated a number of recommendations that the General Board has adopted.
The recalibration of the assessment of the X-ray images has led to a number of adjustments aimed at achieving better coordination between the assessment of the X-ray images of the PROK and the sports inspection. One of the adjustments is the expansion of the number of required X-ray images, with four additional images (two of the fetlocks, two of the stifles). Incidental findings with proven clinical relevance are included in the assessment for awarding the PROK predicate.
The Veterinary Advisory Committee recommends that in the case of a class B or C in the hock (sagittal tibial crest class B-C, lateral roll crest talus class B ) and a class B in the stifle (lateral roll crest femur), the genomic breeding value OC should be taken into account. If the genome breeding value OC is 100 points or higher, a stallion can still be accepted for the performance test. This decision is based on the addition of genetic information represented by the genome breeding value for osteochondrosis. By combining the X-ray images with the genome breeding value OC, the two measuring instruments reinforce each other.

Currently, mares and stallions can be X-rayed for a PROK certificate from April 1 in the year they turn two. This date will be moved to September 1 for stallions, which means that two-year-old stallions will be x-rayed five months later. The Veterinary Advisory Committee indicates that the genetic recovery capacity can still influence the X-ray status between April and September. But other parts of the skeleton are also subject to change in this early developmental phase of the young horse. In addition, it is essential to have up-to-date X-ray images during the stallion selection process. A different arrangement applies to mares: from April 1 to September 1, 2024, it is possible to request the PROK examination under the regular conditions. Starting September 1, 2024, the new conditions described above also apply to mares.

The Veterinary Advisory Committee proposes to initiate a comprehensive study to closely examine the relationship between the presence of kissing spines and clinical signs. Collecting data is considered the most important task. Kissing spines are graded according to the Zimmerman, Dyson and Murray research, with X-rays of the back being classified on a scale of 1 to 7. For stallion selection, classes 6 and 7 are no longer accepted. For mares, an assessment of back and neck photos can be requested, but this still falls outside the standard for obtaining a PROK predicate.

These new requirements will also apply to the stallions in the KWPN-NA licensing process. A detailed explanation will follow in the March issue of the KWPN Magazine, which KWPN members will receive in the second half of March. Do you have any questions or ambiguities that you would like to see addressed? Please send your questions by email to our office: office@ kwpn-na.org
Source: KWPN