Giant panda keepers breathed a sigh of relief on July 10 as a vulnerable baby panda cub has now gained enough weight to survive after being born underweight at southwest China's Chengdu Research Base of Giant Panda Breeding last month. The tiny cub, named Cheng Lang, was smaller than an egg, weighing a minuscule 42.8 grams. In the first two weeks after her birth, little Cheng Lang was unable to feed on milk by herself. After one month of care and attention from breeders, Cheng Lang has now reached a healthy weight of 510.2 grams. Giant panda cubs usually weigh about 150 grams at birth, while those under that weight are considered extremely light.