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Two more pairs of twin panda cubs have been born in a giant panda research centre in southwest China.

 

Three of the new cubs are female and the sex of the fourth is unknown because its mother is still holding it, Li Desheng, deputy director of the Sichuan-based China Wolong Giant Panda Protection and Research Centre, said on Sunday.

 

The births bring to four the number of sets of panda twins born last week at Chinese panda-breeding centers and raises the number of new panda births on the Chinese mainland to 10 for the year.

 

Twin pandas gave birth to twin cubs in a panda research centre based in Chengdu, capital of Sichuan Province, on August 6 and August 7.

 

Five-year-old panda Xi Mei gave birth to twin cubs on Saturday at the Wolong centre, and another panda, Qian Qian, aged 8, gave birth to twins on Thursday.

 

"The two mothers and their cubs are all well," said Li.

 

One of Xi Mei's cubs, a female, weighs 188.9 grams and the other one, being held by its mother, is estimated to be about 200 grams. The 100-kilogram Xi Mei had her first cub last year.

 

Qian Qian, weighing 105 kilograms, gave birth to twin female cubs weighing 190.5 grams and nearly 200 grams. Qian Qian also had a cub last year.

 

"All the newborn pandas this year are heavy," said Li, from the Wolong centre.

 

A 218-gram male cub, the heaviest in the history of China's artificial reproduction program, was born at the Wolong centre on Monday.

 

This has much to do with the improvement of breeding and reproduction management at the centre, Li said.

 

China began artificially inseminating giant pandas in the 1960s, but with very few successful cases. Most newborn pandas weigh between 83 grams and 190 grams.

 

China made a major breakthrough in artificial breeding in the 1990s, with the number of newborn captive cubs rising from nine in 2000 to 25 last year.

 

Giant pandas show little instinctive behavior in captivity, especially sexual desire, according to experts.

 

Experts usually use artificial insemination and encourage pandas to mate naturally.

 

Giant pandas have been around since the age of dinosaurs. They are one of the world's most exotic and endangered species and are found only in China, where they are a national treasure.

 

Studies from the State Forestry Administration show there are over 180 giant pandas living in captivity on the Chinese mainland.

 

(China Daily August 14, 2006)