BEIJING, Sept. 14 -- A cloned, genetically modified cow has given birth to a healthy calf in China, a crucial step toward producing domestic marbled beef.

Ni Hemin, who led the research at Beijing University of Agriculture, said the heifer was healthy half a month after its birth on August 28.

The calf's mother, Niu Niu, is one of two clones born in 2012 with a gene inserted to increase the fat level of their muscle.

Unlike pork where leaner is better, a good amount of muscle fat is key to beef quality. China lacks breeds that produce marbled meat with fat and muscle intertwined, so domestic consumers have to rely on expensive imports.

Ni said the birth of the calf implied major breakthroughs by demonstrating the reproductive capability of GM cattle. Tests on the calf indicated the fat-increasing gene has been passed. The new breed has no more negative impact on the environment than conventionally bred cattle.