The egg quality of Peking ducks was evaluated on three different dates (the beginning, peak, end) of the first egg laying period. During the laying period the following increases were noted: in egg weight (from 71.7 to 86.7 g), in length (from 61.9 to 65.1 mm), in egg width (from 45.0 to 48.8 mm) and in eggshell area (from 81.7 to 92.7 cm2). Percentage of eggshell and albumen have decreased respectively from 10.1 to 9.6% and from 61.2 to 57.1%, while the
yolk percentage has increased form 28.7 to 33.1%. The quality of egg albumen and yolk deteriorated with the age of the ducks. Increases in pH of both yolk (from 5.77 to 6.09) and egg albumen (from 8.06 to 8.70) were noted.
