Chinese scientists announced on Monday a breakthrough in yak cloning: ten cloned calves were naturally born in the Xizang Autonomous Region in southwest China. These calves — three black and seven white — were born between March 25 and April 5 at a yak breeding and research base in Damxung County, Xizang. All of them meet expected standards and are steadily gaining weight. The mass births followed the birth of the first cloned yak in July 2025, which is developing well and currently weighs about 183 kilograms.

The achievement was made using a China-developed breeding system combining whole-genome selection with somatic cell cloning, after three years of research by a Chinese scientific team. Professor Fang Shengguo, from the College of Life Sciences at Zhejiang University and director of the State Center for Conservation of Genetic Resources of Endangered Wild Species, explained that whole-genome selection allows for precise identification of superior genetic loci associated with large body size, rapid growth, high fertility, disease resistance, high feed conversion efficiency, and tolerance to high-altitude, low-oxygen conditions. On this basis, somatic cell cloning makes it possible to accurately replicate the genotype in a one-to-one ratio through asexual rapid reproduction, thereby reducing the breeding cycle to five years.

Yak breeding is one of the key industries planned for development in Xizang during the 15th Five-Year Plan period, covering 2026 to 2030. Traditional yak breeding relied on phenotypic selection — a process that can take up to twenty years and often leads to a decline in genetic quality. Researchers stated that the new method can shorten the breeding cycle to less than five years by precisely identifying desired genetic traits such as faster growth, disease resistance, feed efficiency, and adaptation to high-altitude, low-oxygen conditions, while also enabling the rapid creation of elite breeding populations.

Experts added that this technology could also support efforts to conserve rare yak genetic resources, including the endangered golden wild yak, whose population in Xizang is estimated at more than 300 individuals. To date, the research team has developed more than 200 cloned embryos of golden wild yaks and hybrid wild yaks, laying the foundation for future embryo transfer programs and species restoration.