In rural Buenos Aires province, Kheiron Biotech has created the world’s first genetically edited horses—cloned foals of a prize-winning polo horse with a CRISPR-edited gene to enhance muscle growth and speed. While Argentina embraces cloning in polo breeding, the Argentine Polo Association has banned genetically edited (GE) horses from competition, citing concerns about preserving traditional breeding practices and the sport’s integrity. The breeding association is monitoring the GE horses for several years before deciding on their registration, reflecting broader unease among breeders about the potential impact of gene-editing on their business and international acceptance.

Despite resistance, Kheiron remains optimistic that gene-editing will eventually be accepted, emphasizing education and the technology’s potential to revolutionize horse breeding. The GE foals, born in 2025, will begin polo training in a few years, but commercialization of gene-editing services is paused pending regulatory and industry approval. Experts note that the gene edit—targeting the myostatin gene to increase muscle—mirrors natural variations and could offer a competitive advantage without being unfair, though the long-term effects and acceptance remain uncertain.