An 18-year-old panda, Jiaozi, became the oldest panda in the world to conceive three cubs this year, only one of which was born alive last month.

As she slowly eats bamboo, Jiaozi, also one of the oldest pandas at the Chengdu Research Base of Giant Panda Breeding in Sichuan province, looks no different from her peers.

Yet less than 20 days ago, the 18-year-old who is the equivalent of a 50-year-old in human terms, almost died after her labor from Aug 18 to 21.

A female cub was the only live birth.

In spring, Jiaozi went into heat and she had sex twice on April 25.

"On July 29, she started eating less and her weight dropped to 85 kilograms from 112 kilograms because she had conceived," said Wu Kongju, one of her keepers.

At 7:45 pm on Aug 18, Jiaozi's water broke. At 3:50 pm the next day, the back limbs of a panda cub emerged from the birth canal.

"They looked purple-black as the cub had died. Because the dead cub could not leave the birth canal, Jiaozi had to bite the back of the dead body in order to pull it out. She is a good mother who knew she had to make way for her other two cubs," Wu said.

Research base staff were unable to determine the gender of the stillborn panda.

Thirty minutes later, Jiaozi gave birth to a female cub that weighed 96 grams, much less than the normal weight of 140 grams for a newborn cub. At 4 am on Aug 21, a male cub that weighed 129 grams was stillborn.

After the arduous birth process, Jiaozi ran a fever and would neither eat nor drink. "Her life was at risk," said Luo Li, a vet at the Chengdu panda base.

Vets anesthetized Jiaozi to examine her and found she was suffering from anemia.

"As her veins had collapsed, we had to shave her limbs so we could find veins to inject medicine," Luo said, pointing out Jiaozi's shaved limbs.

After four days of treatment, Jiaozi started eating a little bamboo. The following day, she ate bamboo shoots and started walking around in her den in the evening.

"She is now recovering and weighs 90 kilograms," Wu said.

Because of her illness, Jiaozi cannot take care of her surviving cub, named San'er. Qinghe, a 12-year-old panda who gave birth on Aug 14, nurses San'er every day.

"Panda mothers have loving hearts. They will feed and hold the cub of another panda mother," said Chen Min, San'er's keeper.

"As a panda mother cannot take care of two cubs at the same time, Qinghe breastfeeds San'er when we take her own cub outside her den," she said.

She said San'er receives around 100 grams of milk from Qinghe and gains an average weight of 20 grams each day.

"San'er's weight has risen from 96 grams at birth to 378 grams, nearly the normal level," she said.

According to Hou Rong, a researcher at the base, it is only the third time any panda in the world has conceived three cubs.

"In 1967, a 9-year-old panda at Shanghai Zoo gave birth to three cubs. All the triplets died. In 1999, a 16-year-old panda at Wolong Nature Reserve (in Wenchuan county, Sichuan) gave birth to triplets but only one survived," she said. huangzhiling@chinadaily.com.cn