The Taipei Zoo on Friday carried out artificial insemination in female giant panda Yuan Yuan to help her conceive a second baby.
Zoo veterinarians collected sperm from male panda Tuan Tuan and then injected it in Yuan Yuan, the Xinhua News Agency reported on Saturday.
Tuan Tuan and Yuan Yuan were given as a goodwill gift to Taiwan by the Chinese mainland in 2008, and are around 12 years old.
They had their first female cub Yuan Zai on July 6, 2013, also by artificial insemination.
The zoo keepers noticed several estrous symptoms in Yuan Yuan, including less appetite for food, walking back and forth and making sheep-like sounds since March 13.
They conducted a variety of physical inspections including her hormone index and learned that Yuan Yuan was to reach the peak of her estrous period on Friday, which only happens once a year.
Yuan Yuan was kept away from visitors on Friday. The pair also received a full health examination on Friday, with Tuan Tuan weighing 121 kilograms and Yuan Yuan 118 kilograms.
Huang Yan, chief engineer of the China Conservation and Research Center for the Giant Panda in Chengdu, Southwest China's Sichuan Province, was also invited to assist with efforts to help Yuan Yuan conceive.
Huang and Taiwan veterinarians will strive to make sure Yuan Zai is not the only child, Xinhua said.
According to a 2016 Xinhua report, giant pandas have a low fertility rate because they are sexually inactive.
Female pandas can only become pregnant once a year and have litters of two cubs at most. The gestation period can last from 60 to 120 days.