Tran Van Mui, director of the park, said the animal, a male, had died of old age. 

It had 75-centimeter horns, he added.

Forensic test will be conducted on Wednesday for official conclusion of the cause of death.

Tran Van Mui, director of Dong Nai Culture and Nature Reserve, examines
a gaur's body in the Dong Nai Culture and Nature Reserve, July 23, 2019.
Photo by VnExpress/Thai Ha.

"The gaur’s body will be conserved and used for scientific research," Mui said.

The animal’s body was decomposing when it was found by forest rangers on patrol.

In the last three years three gaurs have been found dead in the reserve. One of them was killed by poachers for its meat, one died of sickness and the other was hit by a vehicle.

The gaur, or bos gauruswas, the world’s largest bovine, is in Vietnam’s Red List since 2006 and protected. It is listed by the International Union for Conservation of Nature as vulnerable.

A 2008 study found only 300 gaurs were left in Dong Nai Culture and Nature Reserve and Cat Tien National Park, part of which is also in Dong Nai.