Four hundred and fifty quails of each sex, in a total of nine hundred quails, were assigned to a completely randomized design with five replicates of six quails per experimental unit, to estimate the crude protein (CP) and metabolizable energy (ME) requirements for maximum performance of females and males Japanese quails reared for meat production purpose and to determine the best slaughter age. The treatments were consisted of the quails sex and the experimental diets, resultant from the combination of five levels of CP (18, 20, 22, 24 and 26%) and three level of ME (2800, 3000 and 3200 kcal/kg of diet), and allotted to the plots and to the four experimental periods, as splitplots. The estimates of CP and ME requirements during the first (5 to 16), third (27 to 38) and fourth (38 to 49 days of age) periods were: 26 and 2800; 18 and 3200 and 19,62% and 3200 kcal/kg of diet for females and 26 and 2800; 18 and 3200 and 18% and 3200 kcal/kg of diet for males, respectively. The CP requirement for females and males in the second (16 to 27 days of age) period was 26%, however it was not possible to estimate the ME requirement for both sexes, in relation to the same period. For the whole period, the estimated crude protein requirement for maximum weight gain of females and males was 24.73%. The estimated ages for maximum body weight depended on the crude protein level of diet and varied from 91 to 189 days of age for females and from 57 to 83 days for males.
crude protein; japanese quails; metabolizable energy; nutritional requirements; slaughter age
