CHENGDU -- The lightest ever premature giant panda, who was abandoned by his mother after giving birth, has survived his first week and is healthy, a veterinarian said Wednesday.

The premature male cub is now more than 80 grams, up from 51 grams when he was born on Aug. 7, said Wang Chengdong, veterinary director with the Chengdu Giant Panda Reproduction and Research Center in southwest China's Sichuan Province.

It is the lightest baby giant panda on record, according to the Chengdu center.

Baby giant pandas are usually more than 100 grams, while those weighing less than 80 grams are unlikely to survive as they are too small to hold onto their mother's teats.

The mother panda, named Qi Zhen, gave birth to a set of twins but the other cub was born healthy. Perhaps knowing that it was almost impossible for the lighter cub to survive, she abandoned him after delivery.

Staff at the Chengdu center put him in an incubator and fed him. However, they spent more than half an hour to feed 0.8 grams of milk on the first day as he was too weak to suck. Staff milked Qi Zhen to feed the cub, which is thought to have been the key to his survival.

"However, we can not say we are successful until he is six months old," Wang explained.

In 1993, the Chengdu center successfully brought up a 61-gram cub dubbed Eryatou. Eryatou, meaning "second girl" in Chinese, gave birth to a 130-gram female cub on Sunday morning after 123 days of pregnancy in the Chengdu center.

This is the fourth birth for Eryatou, but none of her previous cubs survived.

China is witnessing a baby boom among its giant panda population with the most recent cub born in the Chengdu center on Monday night.

The birth brings the number of newborn, artificially-bred pandas to 12 so far this year.

A 218-gram panda, the heaviest in the history of China's artificial reproduction program, was born in Wolong giant panda research and protection center, also based in Sichuan, on Aug. 7.