The Key Role of the Collaboration Between Avantea and Mares of Macha

In the world of sport horse breeding, access to the very best genetic lines has always been one of the most complex and selective aspects of the industry. For many years, the opportunity to breed from mares that have written the history of show jumping has been reserved for a small circle, dependent on long-established relationships, significant financial investment, and constant presence at the highest level of the sport.

It is from this awareness that Mares of Macha was born—a project capable of moving beyond traditional breeding models and turning genetic excellence into a concrete and shared resource.

From top sport experience to a new vision of breeding

Mares of Macha was created from the direct experience in international show jumping of its founders, Klaas De Coster and Yff Vandendriessche—friends for more than twenty years and united by long careers spent among top-level horses, five-star competitions, and a network built at the very peak of the sport.

Thanks to this background, both were able to observe elite breeding dynamics from the inside and understand how difficult it is for the majority of breeders to gain access to the best mares in the world.

The idea behind Mares of Macha arose almost naturally from a shared reflection: if, through their skills and long-standing connections, it is possible to source exceptional mares, why not make this genetics available to those who do not have direct access to that world? This is how the project’s founding concept—Access Proven Breeding—took shape: a philosophy that goes beyond the simple sale of embryos and aims to democratize high-level sport horse breeding.

Rigorous and uncompromising genetic selection

At the heart of the Mares of Macha program lies an extremely strict mare selection process. Every mare admitted to the roster must meet precise criteria that reflect a modern breeding vision firmly anchored in sport results and the strength of maternal lines.

Selected mares have either proven their value directly in competition, with tangible placings in five-star Grand Prix classes, or are bred to stallions that have performed at the highest international level. Alternatively, they descend from maternal lines considered true pillars of global sport horse breeding, being direct daughters of mares that have influenced generations of sport horses.

This approach allows Mares of Macha to build a highly coherent breeding program in which every mare represents a guarantee of quality and a genuine opportunity for breeders.

Transparency and accessibility

One of the most innovative aspects of the project is transparency. In a sector often characterized by private negotiations and variable conditions, Mares of Macha has chosen a clear and accessible model, with fixed and identical prices for everyone, regardless of country or buyer profile.

This principle fits perfectly within the philosophy of Access Proven Breeding: genetic excellence should not be a privilege for a few, but a real opportunity for breeders worldwide. Added to this is the option to choose the sex of the embryo, an essential tool for those wishing to build a strong female line or invest in a horse primarily intended for sport performance.

A truly global vision of breeding

Originally developed in Europe, the Mares of Macha project has rapidly expanded its reach, connecting with breeders in strategic markets such as the United States, Argentina, and Brazil. In these countries, the ability to receive embryos directly on national soil represents a radical change.

Breeders are not simply purchasing a finished product; they become an active part of the breeding process, choosing the matings and maintaining their role as breeders. This approach strengthens the identity of local breeding programs and creates a tangible bridge between elite European genetics and emerging markets.

The collaboration with Avantea

Building an international breeding model such as Mares of Macha also requires precise and well-considered technological choices. This is where the collaboration with Avantea comes into play.

Avantea has been a pioneer in the development and application of OPU-ICSI techniques, making it possible to produce and cryopreserve embryos destined for a global market. At the time the project was launched, this technology was virtually unique and represented the only solution capable of supporting an international breeding vision.

Thanks to frozen embryos, Mares of Macha can overcome logistical and sanitary limitations, work with mares with complex fertility, and use rare or no-longer-readily-available semen, significantly expanding the genetic possibilities offered to breeders.

Efficiency, welfare, and responsible mare management

The adoption of advanced techniques developed by Avantea also reflects a precise ethical choice. Mares of Macha mares are horses that have had top-level sport careers, often competing in Olympic Games, World Championships, and major international events.

Limiting the number of annual interventions, reducing stress, and ensuring a high quality of life are central elements of the program. OPU sessions are few and carefully planned, while for the rest of the year the mares live under optimal conditions, ensuring a sustainable breeding approach.

Data, results, and reliability

Over the years, Mares of Macha has accumulated a significant number of cases that allow a concrete evaluation of the effectiveness of the procedures adopted. Based on the program’s direct experience, success rates after embryo transfer average between 60% and 65%, in line with industry expectations, Yff Vandendriessche told us.

The decision to communicate these performance data transparently reflects the desire to provide breeders with accurate and realistic information, fundamental for building long-term trust.

Innovation and tradition: embryo sexing

One of the most debated topics in modern breeding is embryo sexing. For Mares of Macha, this practice does not represent a threat to genetic heritage, but rather a tool that promotes economic and managerial sustainability.

The possibility of obtaining the desired sex allows breeders to optimize resources, reduce waste, and make sport horse breeding more accessible, especially in markets where demand is strongly oriented either toward sport prospects or toward building female bloodlines.

Looking to the future

Looking ahead, Mares of Macha’s objective remains clear and consistent: to further expand access to quality breeding, introduce new elite mares, and open additional countries to embryo distribution.

Along this path, the collaboration with Avantea will continue to play a central role, supported by a shared vision.

Mares of Macha is not just a breeding project, but a new cultural proposal for the equestrian world. In a constantly evolving industry, Klaas De Coster and Yff Vandendriessche have shown that it is possible to combine genetic excellence, transparency, and responsibility, creating a sustainable and truly inclusive model.

Thanks to its synergy with Avantea, Mares of Macha is helping to write a new chapter in international sport horse breeding, where excellence is no longer a privilege for a few, but a shared resource for building the future of the sport horse.

A. Ceserani

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