Abstract: Method of improving the quality of an egg from a female adult fowl comprising adding an effective egg improving amount of at least one tea polyphenol to a feed composition for the fowl and administering the composition to the fowl. Eggs produced by such method have a reduced crude fat content, a reduced peroxide content, an enhanced Haugh Unit value, an enhanced degree of transparency of egg white, an enhanced foam-forming ability and a pure white color in foam and egg white when the eggs are cooked. Also provided is an improved feed composition for improving the quality of an egg from a female adult fowl, wherein the improvement comprises the feed composition containing an effective egg improving amount of at least one tea polyphenol.