Knowledge
Photograph by ©www.imagesofpolo.com Photograph by ©www.imagesofpolo.com
Cuartetera B03 (pictured) is a clone of Dolfina Cuartetera, one of the 70 horses tested
Polo Genetics What is Behind Argentine Polo Ponies?
Mario Novillo Corvalán MV got in touch with Polo Times with an article by himself and the Applied Genetics Laboratory of the Livestock Breeders Association, published by the YearBook of the Argentine Polo Pony Breeders Association Buenos Aires, 2019, La Dolfina claimed the Argentine Polo Open Championship, at Palermo, for the seventh consecutive year and made history. It was indeed a remarkable achievement, that even overwhelmed other historical marks. But what makes Argentine polo so good? In addition to the extraordinary players, there is a strong focus on horse genetics. Polo ponies come from Thoroughbreds (TB) in which myostatin, a gene related with muscle development, has been associated with the performance of a horse. Myostatin (MSTN) is a negative regulator of the muscle development in mammals. A mutation in the gene produces more precocious racehorses which are able to sprint in short flat races [1]. 42
Polo Times, May 2020
There are three types of Thoroughbreds: 1) the “sprint” types, horses carrying the mutation in two copies that are suited to fast, short-distance races; 2) the “stamina” type, horses without the mutation that are less precocious and are best adjusted for racing long distances. 3) horses, with an intermediate genotype, that carry a single copy of the mutation. MSTN testing has been extended to other horse breeds, like Quarter Horses (Cuarto de Milla), that display the expected sprint type, or Egyptians, with the stamina variety suited to endurance. Therefore, we wonder what type of variety are applied frequently in top Argentine polo horses (AP). In order to answer the
question, we’ve chosen horses ridden in different eras by different teams. A total of 70 horses were tested, including some famous ones: Polo Nevadito (Heguy breeding), Aiken Cura, Dolfina Lapa, Dolfina Cuartetera (all from La Dolfina breeding) and Aguada Anonima (La Aguada breeding). The results are demonstrated in the table (pictured), but all the horse genotypes are available upon request. The first conclusion is the almost absence (4.3%) of the sprint type compared to the 23.4 % observed in local TB. The comparison is relevant based on their shared background. There is a prevalence of the stamina variety among AP horses with a 2.4 ratio of the stamina to sprint type, compared to 0.81 of TB (P < 1.10-4). This significant difference suggests a functional selection for the MSTN gene in AP horses. They were famous for their stamina, featured in horses that play a complete chukka or more than one per match. Things changed around twenty years ago, when polo players started changing horses – sometimes up to three times – during each chukka. Back then, stamina was less required than before, and horses were not as fast as they used to be and gave advantage to the players that replaced the exhausted horses. According to that and the evolution of the sport, a change in the MSTN might have happened in those top horses. We analyzed the MSTN www.polotimes.co.uk
