Mare Genetic Evaluation Report

Horse Sport Ireland Publish Mare Genetic Evaluation Report

 Horse Sport Ireland has today published a Mare Genetic Evaluation Report. Genetic evaluation is a scientific objective, statistical assessment of the genetic merit of horses.  The results of the Genetic Evaluation are published as Estimated Breeding Values (EBVs) and the HSI report provides us with mare EBVs for show jumping ability at international level.  The EBVs measures the difference between each mare’s genetic ability for international level show jumping and the average genetic ability for show jumping for the Irish population.

The report contains three lists of mares:

  1. Mares with ‘Elite BVs’ (representing the top 5% of Irish Sport Horse mares) (Pages 1 to 8, highlighted with a red table border)
  2. Mares with ‘Superior BVs’ (representing the top 25%) (Pages 9 -48 highlighted with a purple table border)
  3. Mares with above average BVs (representing the top 50%) (Pages 48-116 highlighted with a blue table border)

These EBVs are predictions of the genetic advantage that the mare will pass on to its offspring for the trait of show jumping and are calculated using pedigree information and information on each mare’s own performance and from all of its relatives, including parents and progeny. Breeding values change every year as more data becomes available, for example, as the number of a mare’s progeny competing increases.  If you feel there is more data or show jumping results available for your mare please contact us and let us know and we will include all verified results for the next report.

Breeding Values are awarded a reliability value which reflects the amount and type of information used in the calculation of the BV and can range from 0 to 100%.  More information on a horse results in a higher reliability.  EBVs with a low reliability are likely to change, either upwards or downwards, as more information becomes available.  Mare BVs with a reliability below 30% are not published in the HSI report.

Commenting on the publication of the Mare Genetic Evaluation Report, Alison Corbally, HSI Director of Breeding and Programmes, stated “This report is provides breeders with valuable information on the mare herd in Ireland.  The recently published ‘Reaching New Heights’ industry strategy document recommended to profile and benchmark the mare herd in Ireland and I feel that this report goes a long way to meet this goal.  I hope that breeders will find this report together with the Stallion EBV’s in the stallion book to be very informative for this breeding season.”

 CLICK HERE to download the HSI Mare Genetic Evaluation Report.

Information on stallion EBVs are available in the HSI Stallion Book go to

What is Genetic Evaluation?

Genetic evaluation is a prediction of the genetic merit of a horse. It provides an objective, statistical measurement of a mare’s ability to breed international level showjumpers. It is a tool that is useful as part of balanced approach to mating decisions. When assessing the breeding potential of a mare, it is an additional source of information for breeders.

How are the results presented?

The results are presented as Breeding Values (BVs). Breeding values are expressed as an index with an average value of 100 and a standard deviation of 20. The value of 100 reflects the average genetic merit of active breeding mares in Ireland. A horse’s breeding value measures the difference between its genetic ability and the average of the population. For example, horses with breeding values of over 140 are in the top 1% of the population for that trait. The breeding values of mares indicate whether they are predicted to be better or worse than average and range from 50 to 150. Mares successful at international level in showjumping have breeding values over 130.

For example, horses with breeding values of over 120 are considered to be of high genetic merit and are breed improvers. Horses with breeding values over 130 considered to be superior breed improvers. Mares with breeding values over 120 have the potential to breed foals with breeding values over 130 when mated with the correct stallion.

Click here to download the ” Irish Sport Horse Genetic Evaluation Report 2013” which was published in the stallion book.

What do breeding values tell breeders about their mares?

For older mares, it measures the improvement in showjumping ability due to their genes taking all their showjumping progeny at all levels of showjumping into account. Both good and bad progeny are included. Using a high breeding value mare increases the chances of producing an international level showjumper. The chances of a mare with a low breeding value producing an international level showjumper are slim. The breeding values of older mares are mainly based on the showjumping results of their progeny. For younger mares, breeding values measure their potential to produce international level showjumpers in the future based on their own showjumping performances and pedigree. Breeding values based on own performances tell us if a horse is living up to the potential indicated by its pedigree.

What information is included?

The entire showjumping career of a horse and all their relatives are taken into account. Showjumping ability is measured by assessing the highest level in sport at which a horse has achieved two double clear rounds. This is termed the horse’s lifetime performance rating and is assessed in a similar manner to HSI star ratings. Similar methodologies have been researched and implemented by the Dutch and Belgian studbooks. The Dutch genetic evaluation system has been in place for over 20 years and is based on a similar method that focuses on the highest level that a horse has taken part at.

The levels used in the HSI evaluation range from national SJI 1.00m level to FEI Major Championships, e.g. Olympic Games, WEG, World Cup. The main source of results is a combination of SJI and FEI database though other information sources are used when available. For example, it is possible to include national level performances that have taken place outside of Ireland. There are no time or geography limitations on the data that can be included as long as it has been verified by HSI.

How are breeding values calculated?

Breeding values predict the genetic advantage that a horse will pass on to its offspring for a particular trait taking into account all relatives, both good and bad. The genetic evaluation process produces breeding values by disentangling the effects of genes on performance from the effects due to rider, training and luck on the day etc. It also separates out the effects genes inherited from a horse’s sire have on performance from that of the genes inherited from a horse’s dam.

What information is available for breeders?

The primary piece of information given on a mare’s genetic evaluation report is their breeding value. For example, the highest ranking mare at present in the ISH studbook is FLEX, dam of international showjumping stallion FLEXIBLE. She has a breeding value of 150 which reflects her own performance at FEI CSI3* level and her track record of having produced three international showjumpers.

Alongside each breeding value, a number of statistics are provided extra complementary information to breeders. This information can help breeders better interpret the breeding value. The reliability figure reflects how much information is available within the genetic evaluation. Reliability figures range from 0 to 1 for stallions and from 0 to 0.5 for mares. A high reliability indicates that breeding values are not likely to change even if more information becomes available. The genetic evaluation report also contains an edited pedigree report similar to that published in HSI catalogues.

Breeders should note that breeding values from other studbooks are not directly comparable and that a breeding value of 140 abroad is not the same as a breeding value of 140 in Ireland.

How can breeders use breeding values?

If you are aiming to breed high level showjumpers, this corresponds to breeding foals with as high a breeding value as is possible, ideally with a breeding value of at least 130. A foal’s breeding value is the average of its parents so if your mare has a breeding value of 120, you should focus on choosing a stallion with a breeding of over 140. Breeding values for stallions are available in the stallion book and online on the Horse Sport Ireland website. For Irish Sport Horse stallions with breeding values greater than 130, over twenty times as many of their offspring will compete at international level compared to the offspring of stallions with breeding values less than 100 and their foals achieve, on average, €445 more at auction.