A 23-year-old giant panda has delivered twins in southwest China's Sichuan Province, becoming the oldest panda to ever give birth, a breeding centre said on Thursday. The age of 23 for giant pandas was equal to 80 years for a human. The mother, Haizi, gave birth to a 175-gram female and a 123.1-gram male on July 30 at Shenshuping protection base in Wolong National Nature Reserve, according to China Conservation and Research Center for the Giant Panda, Xinhua reported. Haizi became pregnant after mating with a panda called Yibao in April. According to the centre, female pandas reached sexual maturity at seven to eight years old, and the reproduction period lasts for 12 years. Captive female pandas over 20 years old are generally not encouraged to reproduce. Haizi's last delivery was at 19 years old when she gave birth to a pair of twins. She came into season this spring. Since she remained in good health and there was a success story of delivery by a 22-year-old panda before, the centre decided to arrange mating for her. To take care of the senior pregnant panda, the centre allocated a special vet and breeder and tailored a breeding programme for her, said Li Desheng, a panda zoologist with the centre. As of Thursday, 21 panda cubs had been born in the centre this year, including seven pairs of twins. Summer is the peak season for giant panda reproduction.