Chinese doctors have successfully transplanted part of liver from a genetically altered pig to a monkey, a hospital announced on Wednesday in Xi'an, Shaanxi province.

The 10-hour operation was performed on Tuesday by a team of doctors at Xijing Hospital of the Fourth Military Medical University. The recipient was a Tibetan macaque, a species found only in China.

Dou Kefeng, the team leader and a professor at the hospital, said the operation, the result of a four-year research project, was the first of its kind successfully performed in Asia.