The main food of giant pandas is bamboo. 99% of the food of giant pandas is bamboo. There are more than 60 species of 12 genera in bamboo plants available for pandas. In addition, wild pandas occasionally eat dead bodies of other animals or other plants.
Although pandas like to eat bamboo, they are quite particular in it. They like to pick different bamboo species and different parts to eat. Since bamboo is a low-nutrient and high-fiber food, it is difficult to choose a suitable part to eat.
The main fibrous substances in bamboo are cellulose, hemicellulose and lignin. Hemicellulose is relatively easy to be digested, while cellulose and lignin are more difficult to be digested. Some giant pandas would choose pandas with low cellulose and lignin content, such as bamboo shoots and fresh bamboo leaves. Others might pick bamboos that can be excreted quickly, so that they can continue eating more.
Like humans, pandas also like to eat bamboo shoots, but they don’t like bamboo poles and old leaves. However, as bamboo shoots only grow in summer, pandas mainly eat bamboo leaves and stalks throughout the year. When there are bamboo shoots, giant pandas would start eating them vigorously, sometimes even eating 20 hours a day and that’s about 40kg of bamboo shoots!
Even if they only eat bamboo leaves, they would have to eat about 15 kg. The bamboo shoots are a much better choice for them, and they’re so easy to be digested. Bamboo shoots have an extra layer of skin, and pandas have to peels off the skin and eat only the core.