Battling summer heat and dust, child jockey Purevsurengiin Togtokhsuren rides his stallion across the vast Mongolian steppe.

Despite being only 13 years old, Togtokhsuren is riding for the fifth time in the national races for Mongolia's summer festival, known as Naadam, lining up against some 170 other child jockeys.

Riders chant hard to inspire their horses and Mongolians hope to be covered in the dust they kick up -- they believe it brings good luck.

The armies of Genghis Khan and his descendants rode their steeds to conquer a huge swathe of the Eurasian landmass and for 800 years, Mongolians have celebrated Naadam, which showcases the "three manly skills" of horsemanship, archery and wrestling.

The warm temperatures are also a welcome respite from long and brutally cold winters -- the reason Togtokhsuren himself rides horses for money.

His parents sent him to work as a jockey after they lost their livestock during the unusually harsh winter of 2010, known in Mongolia as a zud, in which millions of animals perished.

Togtokhsuren has taken to the sport and says he wants to coach other jockeys in the future, so that he can ride horses his entire life.

But the time away from family has taken a toll.

"I don't know what my parents do for a living while I'm away," says Togtokhsuren, whose serious mien and close-cropped hair give him an air of maturity beyond his years.

"I don't miss my mum because I've been living at my coach's for the last five years," he added.

Togtokhsuren would not say how much he makes, but Mongolian child jockeys usually earn 500,000 tugrik (about $250) a month -- which goes to their parents, while coaches pay for food and school materials.

There are incentives. A first place at the national races -- the most prestigious in the country -- entitles him to 20 percent of 15 million tugrik prize money from by the government, and often more from sponsor companies.

Though bathed in the glow of tradition, racing is also a hazard to the children who mount up -- some have died or suffered serious injuries -- and their plight has drawn the attention of UN agencies such as the International Labour Organization and UNICEF.

Mongolian horses are bred for stamina and distances are far longer than in Western racing.

Togtokhsuren took third and fourth place in Naadam races in 2014, but finished well down the line this year.

He came in 30th in the six-year-old stallion race, a 15-kilometre sprint, and 54th out of 172 in the five-year-old stallion competition, a 23-kilometre event.

But he withdrew from the Ikh-Nas, a run over the same distance for fully mature horses, saying his mount was too feeble to take part.

More than half of Mongolian pastureland has suffered from heat and lack of rainfall in recent months, resulting in little fresh summer grass and a parched look to the steppe.

"Because of the drought my horse is too weak to compete this year."