Chongqing - Zhangmu cattle and Apeijiaza cattle, two endangered breeds found in Southwest China's Xizang Autonomous Region, were successfully cloned in Yunyang County, Southwest China's Chongqing Municipality, scientists announced on January 29, 2024. This marks the world's first successful cloning of endangered cattle species from the Qinghai-Xizang Plateau, the roof of the world, and is a significant breakthrough in the cloning of cattle in China.

Cloned Zhangmu cattle and cloned Apeijiaza cattle at the Chongqing Beef Cattle Breeding Farm, Yunyang County, Chongqing. (Photo provided to iChongqing)

This project, aimed at preventing the loss of genetic resources for endangered cattle species on the Xizang Plateau, was initiated in July 2022. Through live protection, somatic cell cryopreservation, and cloning restoration techniques, the project focuses on rescuing and protecting the critically endangered Zhangmu and Apeijiaza cattle.

Led by Professor Wang Yachun from China Agricultural University, the project formed a research team in collaboration with the Chongqing Academy of Animal Science and Chongqing Jinxia Animal Husbandry Liability Co., Ltd. After strenuous efforts, as of now, the Chongqing Beef Cattle Breeding Farm has successfully cloned four male calves of each breed.

"From the beginning of the project, we prioritized selecting the project site in the five provincial regions in Southwest China to minimize the potential stress reactions when cloned cattle return to Xizang," said Wang Jing, an assistant researcher at the Institute of Animal Sciences of the Chinese Academy of Agricultural Sciences. The choice of Yunyang County in Chongqing was based on its advantages as a traditional county for cattle and sheep farming, along with its suitable climate conditions for the survival of cloned cattle.

As for the plan, from July to August 2024, the research team will return two cloned cattle of each breed to their original habitat in Xizang to meet the urgent need for breeding bulls. Meanwhile, the Chongqing Beef Cattle Breeding Farm will continue cultivating the remaining cloned cattle to adulthood, carrying out training, semen collection, and other activities to enhance breeding efficiency further.

Liu Yonghong, Deputy General Manager of the Chongqing Beef Cattle Breeding Farm, said that the pregnancy rate of the successfully cloned eight cattle is around 60%, and the successful production rate is about 20%, reaching a top-level standard in the field of cloning technology. This project has achieved a monumental result in rescuing and protecting endangered Xizang cattle species. Through somatic cell cryopreservation technology, it successfully addressed the challenges of long-distance transport of somatic cells, providing a long-term solution for protecting cattle species.

This project has not only made significant breakthroughs in the protection of endangered cattle species but also provided new insights into the application of cloning technology in agriculture. Through this successful cloning, projects like this will contribute to the more comprehensive protection of endangered Xizang cattle species, positively contributing to biodiversity and promoting sustainable development in animal husbandry.

 (Zheng Siyu, as an intern, also contributed to the report.)