The study was conductedto estimate requirements of energy and crude protein for maintenance, weightgain and egg production of Japanese quails in the period of 67 to 107 days ofage. Two experiments were performed: one, to determine the requirements formaintenance of protein, and the other, for energy. Experiments were conductedin a completely randomized design with four dietary levels of offer and fourreplicates of six birds. The diets offered were: ad libitum (100%), 75%,50%, and 25% consumption ad libitum (below maintenance). The methodologyused to estimate the demand for maintenance was the comparative slaughter. Forestimation of the requirement for weight gain, eight groups of 15 quails werereared separately, fed ad libitum and housed under 22 ºC controlledtemperature. From these poultry, three groups were slaughtered at 5, 10, 15,20, 25, 30, 35 and 40 days of the trial. The requirement for egg productionwas obtained by taking the ratio of energy content, egg protein, efficiencyof energy use and protein for egg production. Prediction equations that estimatemaintenance requirement, weight gain and egg production in energy and crudeprotein of Japanese quail include: metabolizable energy (kcal/bird/day) = 92.34*bodyweight0.75 + 6.23*weight gain + 4.19*egg mass; crude protein (g/bird/day)= 6.71*body weight0.75 + 0.615*weight gain + 0.258*egg mass.
