Nui Chua National Park to preserve precious gene pool of hybrid gaurs

Preserving the “mark of the green forest” within the Bac Ai mountains

From the dipterocarp forests of Nui Chua - Phuoc Binh National Park, located in Bac Ai Tay commune, Khanh Hoa province (formerly Phuoc Binh National Park in Phuoc Binh commune, Bac Ai district, Ninh Thuan province), scientists have been diligently carrying out a special mission: “Conservation and sustainable use of the F1 hybrid gaur gene pool.” This herd is the result of a rare natural crossbreeding between domestic cattle (Bos taurus) and wild gaurs (Bos gaurus).

Guiding us to visit the 11 hybrid gaurs, Nguyen Anh Tuan, Deputy Head of the Department of Resource Management and Biosphere Reserves of Nui Chua (Phuoc Binh National Park), warned that filming and photographing must be done from a distance because the animals retain their wild nature and aggressiveness. Understanding our curiosity upon seeing that some had black coats while others were yellow coats, he explained that the black ones were males, and the yellow ones were females.

“To keep the hybrid herd strong, shiny, and healthy, the Park hires two local workers for daily care, one to watch the herd when it grazes and another to clean the barn and cut grass for feeding,” said Nguyen Anh Tuan.

According to scientists, the number of wild gaurs in Vietnam has decreased by over 90%, from more than 3,000 individuals in the 1970s to only about 300 scattered across forests in the Central Highlands, Khanh Hoa, and Dong Nai. The species is classified as endangered with a high extinction rate due to habitat loss and rampant poaching. Among these, Khanh Hoa is one of the few provinces where a gaur herd has been recorded at Nui Chua - Phuoc Binh National Park, which is considered home to one of the country’s largest remaining populations.

The story of the hybrid gaurs in Nui Chua - Phuoc Binh National Park dates back to 2009, when residents of Bac Ray 2 village in the Park’s buffer zone noticed a male gaur frequently joining domestic cattle herds to graze.

Natural mating occurred, and soon after, calves with black coats, white legs, aggressive temperaments, and rapid growth appeared. These were the F1 generation, the first natural hybrids between gaurs and domestic cattle.

To confirm their origin, between 2012 and 2014, the Ninh Thuan Department of Science and Technology and the Lam Dong Department of Science and Technology commissioned Phuoc Binh National Park and the Lam Dong Center for Scientific and Technological Applications to conduct a joint study titled “Genetic identification and reproductive capacity assessment of F1 hybrids between domestic cattle (Bos taurus) and wild gaurs (Bos gaurus) in the border forests of Ninh Thuan and Lam Dong.”

The results showed that 10 F1 hybrids had 58 chromosomes (2n = 58), consistent with the genetic theory of crossing domestic cattle (2n = 60) with gaurs (2n = 56). This marked the first time Viet Nam confirmed the existence of naturally hybridized gaurs - a rare  phenomenon in wildlife conservation research.

Scientific research paving the way for conservation

Since 2015, a project titled “Development and utilization of rare cattle genetic resources in the border forests of Ninh Thuan, Lam Dong, and Khanh Hoa,” led by Dr. Le Xuan Tham, former Director of the Lam Dong Department of Science and Technology, has been implemented.

The research team identified the reproductive ability of first- and second-generation hybrids and established technical procedures for care, feeding, disease prevention, and forage cultivation for the rare herd. Around the same time, villagers in Bac Ray 2 also recorded cases of F1 hybrid cows giving birth.

Six research activities were carried out under the project. Results revealed that F1 hybrid cows could reproduce, producing calves with 25% gaur blood and a balanced 60-chromosome set (2n = 60) when mated with domestic cattle. F1 hybrid bulls also passed on genetic traits when crossbred.

Outcrossed F2 hybrids exhibited good growth and reproduction, producing healthy F3 offspring. Mature F1 hybrids outweighed yellow cattle and Sind crossbreeds, while F2 hybrids grew as large as Sind crosses.

However, inbreeding (mating F1 males and females from the same line) to create F2 hybrids with 50% gaur blood was unsuccessful despite 94 mating attempts over three years. This proved the genetic limits of narrow-line breeding and indicated that backcrossing with domestic or other foundation breeds is necessary to maintain hybrid vigor.

To continue preserving this valuable genetic resource, Ninh Thuan authorities designated Phuoc Binh National Park as custodian of the national gene fund project assets. The park has since taken charge of raising, conserving, and making the most of the hybrid gaur genetic resources under the project “Development and utilization of rare cattle genetic resources in the border forests of Ninh Thuan, Lam Dong, and Khanh Hoa” for the 2021 - 2025 period.

According to Nguyen Anh Tuan, after intensive care since 2021, the herd’s condition has stabilized. Males weigh 700 - 800 kg, and females weigh around 500 kg, with regular health monitoring. “Hybrid gaurs retain their wild temperament, making close contact, health checks, and vaccinations difficult. We had to build a reinforced steel enclosure, assign a dedicated veterinarian, and follow strict safety procedures,” he said.

The care routine includes a special diet of dry straw, fresh grass, concentrate feed, mineral salts, and preventive medicines. The 2021 - 2025 budget totals nearly VND 2.5 billion, most of which goes toward building enclosures and grazing facilities.

Today, the botanical area of Nui Chua - Phuoc Binh National Park serves as the official care and breeding site for the hybrid herd. The 3-ha semi-wild enclosure, surrounded by strong fencing and featuring open grasslands and dipterocarp forests, provides an ideal environment for maintaining and developing future hybrid generations.

Keeping the “forest bloodline” alive for future generations

Despite positive results, conserving the hybrid gaur gene pool remains challenging. Nguyen Anh Tuan explained that limited breeding and research facilities are the biggest obstacles. Without a foundation herd for backcrossing, the chance of producing calves with balanced 60-chromosome sets remains low.

“We hope that among the current individuals, one male calf with 60 chromosomes can be born. That would be a major scientific breakthrough. Its semen could be used to breed and expand this rare genetic line across Vietnam and beyond,” said Tuan.

Another proposed approach is to collaborate with research institutes and livestock companies to continue monitoring and expanding hybridization programs. Crossing domestic or foreign cattle with F1 or F2 hybrids could help maintain hybrid vigor and genetic diversity.

On another note, Nui Chua - Phuoc Binh National Park partners with Saigon Zoo and Botanical Gardens, which has experience in caring for wild animals, to ensure scientific and safe management of the herd. The park’s Center for Forest Environment Education and Services also organizes conservation education programs for students and visitors to raise public awareness of biodiversity protection.

Currently, the hybrid gaur herd at Nui Chua - Phuoc Binh National Park consists of 11 individuals spanning three generations. The youngest are around 12 years old, while the first F1 hybrids are 15 - 16 years old and nearing the end of their reproductive cycle. Nguyen Anh Tuan believes that the next 3 - 5 years are a “golden window” for research, breeding, and genetic conservation.

“Gaurs can reproduce only until about 20 years old. If we miss this window, the valuable gene pool could disappear. We hope to collaborate with national and international researchers to continue breeding and conserve the gene pool in the long run,” he said.

The conservation and sustainable use of the hybrid gaur gene pool not only preserves Vietnam’s rare natural heritage but also lays the foundation for livestock breeding research, thereby improving animal productivity and resilience to the dry climate of central Vietnam.

“This project is not just about conservation. It opens a path for Vietnamese science to advance further into the field of wild animal genetics. We are working each day to ensure that not a single drop of the forest blood is lost,” Tuan affirmed.