Gonçalo Torrealba Comments on the Genetic Origins of the Thoroughbred Horse

The English Thoroughbred horses are noble and elegant animals whose ancestors come from the same lineage. They have been bred for centuries on farms like Three Chimneys, led by Gonçalo Torrealba, which aims to preserve the tradition and history of the Thoroughbred breed.

Below, learn more about the genetic origins of the English Thoroughbred horse, with insights from Brazilian industry executive Gonçalo Torrealba.

Purebreds and the Thoroughbred Horse

There are many types of purebred horses, such as the American Quarter Horse, the Irish Sport Horse, and the Friesian. However, the English Thoroughbred is considered the most valuable horse breed in the world. Due to its impressive athleticism, it has been used in racing for centuries.

“The English Thoroughbred is definitely the most sought-after breed for horse racing. No other breed can compete at its level—this is why they dominate professional thoroughbred racing,” says Gonçalo Torrealba, president of Three Chimneys Farm.

English Thoroughbreds were developed in the 17th century through the breeding of local English mares with Arabian and Berber stallions. The typical Thoroughbred has some distinctive traits, such as a slim body, long neck, short and broad back, and elongated legs.

The horse may range from 62 to 68 inches high, averaging 64 inches, and weigh around 1,000 pounds. Thoroughbred coats are, in general, colored chestnut, black, bay, brown, or gray.

For a foal to be registered as a Thoroughbred in the Stud Book (the official registry of Thoroughbreds), it must be the result of a witnessed natural mating between a stallion and a mare, a process known as covering.

Breeding typically happens at places like Gonçalo Torrealba’s Three Chimneys Farm, which houses and trains stallions and mares. Stallions can race until around the age of three before starting their career as breeders.

Origins of the English Thoroughbred

The modern English Thoroughbred is a result of centuries of selective breeding. It is believed that the origin of the Thoroughbred breed is linked to the arrival of Berber and Arabian horses in England as early as the third century. People interested in horse racing promoted selective breeding among foreign and native horses, which created different breeds.

Fast-forward to the 17th century, during the reigns of James I and Charles II, 43 English mares, known as the “Royal Mares,” were selected to breed with three stallions: the Byerley Turk (1680s), Darley Arabian (1704), and Godolphin Arabian (1729), from Turkey, Syria, and North Africa, respectively. The English Thoroughbred was officially created by breeding these animals, and horses started being registered in the General Stud Book, first published in 1791.

“Through genetic selection, English Thoroughbred horses became athletes with extraordinarily high aerobic capacity in relation to their skeletal muscle mass,” explains Gonçalo Torrealba.

In addition to training and diet, Torrealba explains that, according to some studies, the speed and endurance seen in Thoroughbreds are also due to mutations in the myostatin gene. Known as the ‘speed gene’ (MSTN), the myostatin gene is a protein that inhibits the growth of skeletal muscle.

Where Did the ‘Speed Gene’ Come From?

Through selective Thoroughbred breeding, the frequency of the myostatin gene variant with “C” copies, which is more common in Thoroughbred sprinters, has increased. A study published in Nature Communications traced the origin of this “speed gene” in racehorses, linking it to a British mare that lived around 300 years ago in the United Kingdom.

The researchers used computational genetics and pedigree analysis to examine the DNA of hundreds of horses.

They analyzed more than 20 breeds, including both British and Irish horses (from which the female Thoroughbred lineage originates) and Arabian, Berber, and Turkish horses (from which the male Thoroughbred lineage is derived). The analysis also included genetic material from the remains of 12 stallions that lived between 1764 and 1930.

The research enabled investigators to pinpoint the exact British mare that carried the original speed gene. This speed gene is responsible for limiting myostatin production in Thoroughbreds, influencing the development of their skeletal muscles and enhancing their racing abilities.

“Studies like these allow professionals working in breeding operations, such as Three Chimneys, to understand the past and develop new techniques and procedures that make purebred horses even more powerful and rapid,” notes Gonçalo Torrealba.

Thoroughbred Breeding at Three Chimneys Farm

Based in Midway, Kentucky, Three Chimneys Farm is one of the world’s leading horse breeding facilities. Since 2013, the year that Gonçalo Torrealba started leading the operation, Three Chimneys has bred high-performance athletes, including Graded stakes winners like Early Voting, fillies Royal Approval and Twenty Carat, and the impressive Gun Pilot, a millionaire, Grade 1-winning son of Gun Runner.

Since the Brazilian executive’s arrival, Three Chimneys Farm has been focusing on blending traditional Thoroughbred breeding techniques with innovative approaches.

In 2023 alone, Three Chimneys Farm’s Thoroughbreds generated over $5.6 million in race earnings, according to Equibase and America’s Best Racing. This figure reflects years of physical training and genetic selection.

Gun Runner, for example, the leading stallion at Three Chimneys, stands at the farm for $250,000. Born in 2013, the son of stallion Candy Ride and mare Quiet Giant joined Three Chimneys in 2014. The Thoroughbred had an extensive racing career from 2015 to 2018, recording 12 wins in 19 races and earning more than $15.98 million.

“In 2024, Gun Runner, whose breeding services we offer at Three Chimneys, was inducted into the Racing Hall of Fame. He is already the sire of 13 individual millionaires, 10 of whom are Grade 1 winners,” says executive Gonçalo Torrealba.

“Gun Runner is continuing to prove our dreams can become a reality, and Three Chimneys and our partners continue to breed our best mares to him, which we believe will further his influence on the breed,” explained the chairman. “We are excited to also bring home one of his promising grade 1-winning sons in Gun Pilot, who was bred and raised here at Three Chimneys.”

About Gonçalo Torrealba

Three Chimneys Farm’s owner, Gonçalo Borges Torrealba, has been a businessman in the Thoroughbred industry for decades. Torrealba began his journey in this field while still in Brazil, where he founded TNT Stud. For more than two decades, the TNT Stud was considered one of the largest breeding operations in Latin America.

In 2013, Gonçalo Torrealba took over as president of America-based Three Chimneys Farm. Since setting foot in the bluegrass hills of Kentucky, Torrealba has transformed the North American Thoroughbred breeding operation into one of the most respected in the world and a breeding ground for champions.