Ginkgo-leaves additions were made to the control diet at the expense of wheat bran.The dietary total flavonoids and polysaccharides contents for the layers are shown in Table 3. All the diets were prepared every other week. Birds were allowed ad libitum access to mash feed and water through the experiment and were exposed to a 16:8 light:dark cycle. All procedures were approved by Nanjing Forestry University Institutional Animal Care and Use Committee.