Abstract: There were two feeding trials in this research. 225 37-week-old Lohamann laying hens were randomly divided into five treatments for trial one,fed a basal diet supplemented with 0, 0.05, 0.1, 0.2, 0.4 percentage tea polyphenols(TP) for a period of 59 days, respectively.600 51-week-old Lohamann laying hens were randomly divided into four treatments for trial two, fed a basal diet added with 0, 0.025, 0.05, 0.1 percentage TP for a period of 8 weeks, respectively. Dietary effects of TP supplementation on performance, lipid metabolism and egg quality were investigated in laying hens. The results showed that: (1) Egg production and feed conversion efficiency were improved to a certain extent by supplementing TP, but they were not improved with the increasing levels of added TP. (2) The addition of 0.1% TP in diet increased egg yolk VE and VA concentration by 58.99% and 20.96%, respectively. And TP was tended to increase whole egg amino acid levels containing S. The supplementation of 0.025%—0.1% TP in diet of layers at later period decreased broken and soft-shelled egg rates by 31.59%—47.09%. (3) The addition of 0.4% TP in diet decreased total cholesterol (TCH), triglyceride(TG), LDL-C contents of layer serum with 46 week old by 19.65%, 19.99% and 7.69%, respectively, and increased HDL-C by 45.35%. No significant change of 0.025%—0.1% TP supplementation on serum lipid levels was found in layers with 59βw old.

Key words: Tea polyphenols, Performances, Lipid metabolism, Egg quality, Laying hens