The aim of thisstudy was to evaluate the effects of reduction of energetic density of the dieton the quality of Japanese quail eggs, keeping the same metabolizable energy(ME):nutrients relationship. It was used 400 Japanese quails from 76 to 160days of age, distributed in a complete random design, with five treatments,10 replicates and 8 birds per experimental unity. It was used five diets withdifferent energetic densities (2,900; 2,800; 2,700; 2,600; and 2,500 kcal ME/kg),keeping constant the relationship between metabolizable energy and nutrientsof the diet, which had 2,900 kcal ME/kg. Diet was fed ad libitum during allthe experimental period. There was a significant difference only on the rationintake and on the egg specific weight. It was not observed significant differenceamong diets for the following parameters: metabolizable energy intake, crudeprotein and amino acids, egg weight, egg mass, yolk weight, yolk percentage,albumen height, albumen percentage, shell weight, shell percentage, egg diametersand egg height. Diets with 2,800 and 2,900 kcal ME/kg, by keeping constant metabolizableenergy:nutrients ratio, provide the same egg quality.
