Abstract: Indices of feed rewarding rate, output value rate, direct expense coefficient, conversion efficiency of feed energy to egg energy and ecolomic benefits are used to calculate and analyze the experimental results obtained under three optimized diet combinations. The function En=at^bc^-et is applied in simulating and modelling egg-laying patterns under different diet combinations. The results can be of guidance in egg-laying hens management and in prediction of egg productions.

Key words: Picea likiangensis, radial growth, climate change, dendrochronology； Small Zhongdian area