CHENGDU, Oct. 13 (Xinhua) -- The China conservation and research center for the giant panda has celebrated the birth of a record 42 panda cubs this year.

The 42 cubs were born to 30 mothers. The 17 born at the Ya'an Bifengxia base in Sichuan made their debut Friday. The others met the public at Shenshuping protection base in Wolong National Nature Reserve.

Keepers at the centers have been on duty around the clock since May to ensure the pandas are happy and healthy.

"The number of cubs born this year shows our preservation and breeding techniques have matured," said Zhang Hemin, deputy head of the center.

The estrous rate of pandas was 95 percent, while fertility rate and survival rate of cubs reached 87 percent and 95 percent respectively this year, Zhang added.

With the development of breeding technology, the number of giant pandas born in captivity in China has risen from just six in 1983 to 273 this year, accounting for over 60 percent of the world's captive pandas.

Giant pandas are endangered and live mainly in the mountains of northern Sichuan Province as well as southern Gansu and Shaanxi provinces.