A horse pedigree doesn’t jump, but rather the product of a crossbreeding — once it has been born, raised, broken in…
The breeder’s reasoning is complex and depends on their personal goals.
The choice of a specific crossbreeding will differ depending on whether the goal is to sell the foal, bring the horse to age three before him up for sale, or compete with him.
Beyond the standard information found in almost all stallion advertisements — pedigree, progeny, performance, price, and strengths — we have always strived to go one step further by displaying our stallions’ fertility and describing them as accurately as possible, including their less favourable traits.
This is how we came up with and developed the PAX programme (Breeding Advice Programme) 10 years ago.
The first version (still online at www.gfeweb.com) took 44 criteria into account and explained why and how to measure them before submitting them to the PAX algorithm to assess the relevance of the crossbreeding project.
The first five years of use revealed that characterizing certain criteria (e.g., walk, balance, long lines) was too complex and that others were not heritable enough to be useful. In 2019, we therefore launched the second version, called Graphical PAX.
GRAPHICAL PAX – INTERPRETATION
The new version includes 21 criteria, each with a “recommended zone” — the score range which we recommend to optimize the future offspring’s athletic potential. Each of our stallions is rated, and based on the mare’s ratings, the algorithm calculates the probable scores of the resulting foal.
A yellow curve (the probability of the offspring’s rating) within a green zone (recommended range) provides a quick overview of strengths and risks related to each crossbreeding.
The system has been well received and widely used. From our discussions with users, we found that 11 of the 21 criteria were the most frequently assessed. These were grouped into a quick analysis formula called PAX Express, launched in 2024.
The 11 criteria are the following: shape, head, height, bone structure, canter scope, foreleg technique, hindleg technique, strength, blood, courage, and carefulness. Represented as 11 targets, each lights up as the mare’s traits are scored:
● Green: good compatibility with the chosen stallion
● Orange: average compatibility
● Red: low compatibility
Once at least 3 of the mare’s traits are scored, the stallion’s name is displayed on a color-coded background (dark green / light green / yellow / orange / red) based on the number of green, orange, and red scores.
Dark or light green-rated crossbreedings can be pursued without concern; yellow or orange crossbreedings require further review (see full Graphical PAX), whilst red ones should be avoided.
PAX EXPRESS – FUNCTIONALITY
To test the reliability of our PAX Express tool, we analyzed archived data from over 800 mares, each evaluated using at least 7 of the 11 PAX Express criteria. From this group, we selected 251 mares whose offspring (a total of 313 horses) were sired by GFE stallions and had available competition results in show jumping.
We then applied the PAX Express “colour code” that would have been given at the time of breeding and sorted the horses into three groups:
121 horses = dark green (PAX would have recommended the cross)
114 horses = light green (PAX would have approved the cross)
106 horses = orange/red (PAX would have issued a warning)
Next, we calculated the average performance score for each group. These scores are based on the French national show jumping index (ISO), where 100 is the average score for all horses competing in France. Here are the results:
Orange/red group: average score = 106
Light green group: average score = 114
Dark green group: average score = 121
While there are always exceptions — some “not recommended” crosses produced successful horses, and some “recommended” ones didn’t — the overall trend shows a clear correlation between the PAX Express colour rating and later performance in sport. These early results reinforce the tool’s value for making informed breeding decisions.
PAX TIPS - CLUES
