

On March 30, 2013, veterinarians at the National Zoo artificially inseminated Mei Xiang after natural breeding failed to occur. This was because the lungs were not fully developed, and consequently the lungs were unable to pick up oxygen for the red blood cells to deliver to the liver. The cub's death was determined to be the result of insufficient oxygen to the liver. However, it showed fluid in the giant panda cub's abdomen (which is usually abnormal), and some discoloration of some of the liver tissue. Initial findings from the necropsy ruled out the possibility that it could have been crushed by Mei Xiang. The cub, whom officials believed to have been a female, was found deceased on Septemafter Mei Xiang expressed distressed, honking-like sounds. As of September 17, zoo officials did not know the sex of the cub. Another cub was born on the night of September 16, 2012, and was a surprise to zookeepers. Zoo officials estimated her chances of pregnancy at 10% after she had previously had five false pregnancies, in which she acted pregnant but was not. Mei Xiang was artificially inseminated twice in April 2012 with Tian Tian's sperm. He lived at the zoo until February 4, 2010, when he moved to China, as per an agreement between the United States and China. He was the first panda cub to be born at the zoo and live for more than a few days. Mei Xiang munching on bamboo in November 2017 at the Smithsonian National Zoological Park in Washington D.C.
