Effects Of Fiber-likes And Silicon On The Selective Bamboo Feeding Of Giant Panda

The giant panda (Ailuropoda melanoleuca) is one of the most endangered species in the world, and depending almost exclusively on bamboo. However, when feeding the bamboo, the giant panda is very selective both on bamboo species and bamboo body parts. The mechanism for the selectivity was not fully known. To seek the reasons behind is undoubtedly necessary for the scince, also referencable for corridor design of in situ conservation, and for the captive feeding of ex situ conservation.This study, by using a cafeteria trial, observed 8 captive giant pandas feeding on 10 species of bamboo, during April to May of 2015, in Dujiangyan Base and Bifengxia Base of China Giant Panda Conservation and Research Center, Sichuan. The filter bag technique of Van Soest and PE Optima 8000 ICP-OES were used to determinate the contents of fiber-like substances and silicon elements in the trial bamboos. Correlations between giant panda selectivities and chemicals were analysed. The main findings are as follows:1. For 10 bamboo species, only 8 of them were selected by giant pandas. For bamboo body parts, the feeding rates were 59.68% for shoot skin,100% for shoot inners,13.53% for culm skin,91.7% for culm inners, and 20.85% for leaves. When feeding the shoot and culm, giant pandas peeled their skins with varying degrees. They also fed only 4 bamboo species leaves, with very lower feeding rates.2. The contents of hemicellulose were significantly varied in different bamboo species. Also, varied in different bamboo body parts, e.g.36.02% for shoot skin,29.56% for shoot inners,18.14% for culm skin,24.49% for culm inners, and 32% for leaves.3. The contents of cellulose were significantly varied in different bamboo species. Also, varied in different bamboo body parts, e.g.31.39% for shoot skin,39.64% for shoot inners, 44.6% for culm skin,38.45% for culm inners, and 22.12% for leaves.4. The contents of lignin were significantly varied in different bamboo species. Also, varied in different bamboo body parts, e.g.10.48% for shoot skin,6.35% for shoot inners, 28.93% for culm skin,22.52% for culm inners, and 14.11% for leaves.5. The contents of silicon were significantly varied in different bamboo species. Also, varied in different bamboo body parts, e.g.4.44% for shoot skin,3.51% for shoot inners, 9.47% for culm skin,2.46% for culm inners, and 25.88% for leaves.6. There were relative weights for different chemicals at different bamboo parts, e.g. more hemicellulose in shoot skin, more cellulose in shoot inners, more lignin in culm skin, and more silicon in leaf. A significant correlation was found between hemicellulose and lignin. Same functional trends were found in cellulose and lignin. also in hemicellulose and silicon.7. When feeding shoot, the peeling rate was negative correlated with cellulose and silicon in shoot skin, but positive correlated with hemicellulose in shoot inners. When feeding culm, the feeding rate was negative correlated with silicon in culm skin and lignin in culm inners, but positive correlated with cellulose in culm inners. The culm peeling rate was negative correlated with cellulose in culm skin and silicon in whole culm, but positive correlated with hemicellulose in culm inners. When feeding leaves, the feeding rate was negative correlated with silicon in leaf, but positive correlated with hemicellulose in leaf.8. The average feeding rates for different bamboo parts were also negatively effected by three kinds of chemical combinations, e.g. total 4 chemicals, hemicellulose+lignin+silicon, or lignin+silicon.