Boet 516 offspring to be monitored


The approval of stallion Boet 516 has of late led to a heated debate within the KFPS. The fact that the approval report of last year´s star of the Central Examination lists a deviating image relating to roaring, has prompted quite some questions. This is reason for a more detailed explanation from the side of the KFPS and how we aim to respond to the raised concerns.

Correct procedures

At an earlier stage the Board had already communicated that the approval of the stallion in question was not in breach of regulations. The conditions for taking part in the CE state that during the performance test the stallions will be subjected to tests for roaring by means of endoscopy/laryngoscopy. The text indicates that any deviation found after a laryngoscopy can be reason to discontinue the CE. Therefore in terms of regulations, a rejection is by no means self-evident. The Board is aware that the members have experienced this differently. After all, in the past fifteen years all cases (as far as we know four in total) with a deviation have always been reason to reject the stallion. The Jury also adopt a very prudent attitude in the face of stallions with a deviating image concerning roaring. In practical terms, a deviation in relation to roaring results in a discontinuation of the CE in 99 out of 100 cases. This depends on the degree of the roaring deviation and the qualities of the stallion in question regarding breeding goal characteristics such as exterior and sport aptitude. The Board points out that in the previous four cases the stallions concerned were afflicted with a more severe degree of roaring and/or had less quality.

Jury appraisal

The Board has also previously communicated that the investigation and decision-making by the Jury had taken place in a correct and conscientious manner. On two occasions an endoscopy was carried out, once in Exloo and once at the Veterinary Faculty in Utrecht. The reason was that, no matter what the final decision about the stallion would be, no doubt should arise as to the diagnosed condition of roaring. In the first place because the stallion does not produce the roaring-specific sounds in training, and secondly because the picture of an endoscopy is in a sense, just a snapshot in time. In this case however, both tests came up with similar results. The Faculty report stated that the stallion fell in the category of ‘just below acceptable’ according to the KWPN standards. This is actually, not a routinely recognised category. The KWPN Assessment Committee works with the following categories: all right; acceptable; just acceptable and not acceptable. By including the word ‘just’ the Assessment Committee intended to add a bit of nuance.

After this the Jury sought advice regarding all aspects of roaring (variations in clinical pictures, causes, genetic aspects, etc.) from for instance Prof. Dr. Sloet, who supervised the endoscopy that was carried out at the Faculty. In the end the Jury came to the conclusion that approval was justified considering the exceptionally positive image of the stallion with regard to exterior and performances, in combination with the fact that this is a mild form of roaring.


The March issue of Phryso will run a feature with more detailed information about roaring, including the genetic aspects. Roaring can have various external causes, such as a cold, strangles/glanders, trauma to the neck, Vitamin B1 shortage, etc. In over 90% of cases however, the cause remains unknown. But this does not mean that roaring has a 90% hereditary component. The hereditary aspects of roaring have only been marginally researched. Research has for example been conducted to find the (potential) genes that are responsible. The fact that this was not successful already implies that the heredity of roaring is probably of a far more complex nature than with for instance dwarfism and hydrocephaly. Still, the research definitely suggests that roaring has a hereditary component, which was also reason to include a remark in Boet 516´s report that breeders have to factor in an increased chance of roaring in offspring.

Monitoring offspring

The Board is aware that this remark does not make it any easier for breeders to make up their minds. On the other hand, more concrete information is not available. Just as with other characteristics, only progeny testing can shed light on what characteristics stallions pass on to offspring. Individual breeders therefore have to make up their own mind. The Board has decided that all Boet 516 offspring will be monitored for signs of roaring by carrying out scopes and to compare the results with a control group. In case the stallion´s offspring prove to have a significantly higher occurrence of roaring than average, then this approach helps to limit breed-technical damages. The method (age, numbers, etc.) of conducting this monitoring will be defined in the next few months.


However, the question still remains whether or not stallions with a deviating image for roaring should be approved. In other words, should roaring be more firmly contextualised in the regulations. And if so, how should the standards be defined. Because in actual effect, the category ‘just acceptable’ is in a way also a deviation. The Board has consigned this question to the Breeding Council who will soon come forward with a motion for an amendment of regulations.

Animal welfare

Members have also asked questions about the relation between roaring and animal welfare. As a general rule, roaring produces no adverse effects in relation to welfare. Roaring can however, have a negative impact on performances in the sport, mainly in endurance sports.


As previously mentioned, publication of the stallion approval reports was too late. Even though publication took place well in advance of the breeding season, this is not appropriate. From now on publication of the reports will take place in the week following the approval.