Two pandas at the National Zoo attempted to mate before zoo officials determined they had not been successful and artificially inseminated the female, Mei Xiang.
Zoo officials say Mei Xiang and Tian Tian tried to mate Saturday night. After carefully observing the pair for several hours and determining mating had not been successful, the pair were anesthetized and semen from Tian Tian was removed to inseminate Mei Xiang. Zoo officials say timing is critical in panda mating because there is only about one day a year in which conception can occur.
Mei Xiang was also artificially inseminated last year, but she did not give birth. Mei Xiang and Tian Tian have produced one cub, Tai Shan (tie-SHON), who was born in 2005 following artificial insemination.