Prediction equations to estimate the demand of energy and crude protein for maintenance, gain and egg production for laying Japanese quails

The study was conducted to estimate requirements of energy and crude protein for maintenance, weight gain and egg production of Japanese quails in the period of 67 to 107 days of age. Two experiments were performed: one, to determine the requirements for maintenance of protein, and the other, for energy. Experiments were conducted in a completely randomized design with four dietary levels of offer and four replicates of six birds. The diets offered were: ad libitum (100%), 75%, 50%, and 25% consumption ad libitum (below maintenance). The methodology used to estimate the demand for maintenance was the comparative slaughter. For estimation of the requirement for weight gain, eight groups of 15 quails were reared separately, fed ad libitum and housed under 22 ºC controlled temperature. 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 production was obtained by taking the ratio of energy content, egg protein, efficiency of energy use and protein for egg production. Prediction equations that estimate maintenance requirement, weight gain and egg production in energy and crude protein of Japanese quail include: metabolizable energy (kcal/bird/day) = 92.34*body weight0.75 + 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