South Korean researchers say they've successfully cloned pigs using stem cells extracted from a donor pig’s bone marrow.

Lead researcher Lee Eun-song of Kangwon University said the extracted stem cells were transplanted into eggs, which were then implanted into the womb of a surrogate mother pig. The process led to the birth of four cloned piglets on December 3rd. Lee said two of them were growing well and in good condition.

The research team leader went on to say that stem cells from bone marrow promised higher success rates than somatic cells, adding that the process was more effective in producing healthy cloned pigs.

The team is planning to submit related papers to academic journals and continue research with the goal of producing transplant organs for humans.

Lee’s research is being conducted as part of the state-run Rural Development Administration’s Bio Green Research Project.