Metabolizable energy requirements for maintenance and growth of broilers

This work was conducted to determine the energy requirements for broilers using the factorial method. The metabolizable energy (ME) requirements for maintenance (MEm) were determined at 13, 23 and 32 degrees C (+/- 2 C) by the comparative slaughter technique. ME requirements for weight gain were estimated considering the net efficiency of energy utilization for growth and body energy content. The energy requirements for maintenance were of 159.36, 116.17, and 128.66 kcal/kg(0.75)/day at 13, 23, and 32 degrees C, respectively, and quadratic effect of temperature (T) on the maintenance requirement (MEm = 300.14 - 14.61 T + 0.2876 T-2, r(2) = 0.90) was detected. Metabolizable energy requirements for weight gain for males and females were of 3.72 and 3.98; 4.21 and 3.93: 4.51 and 7.04 kcal/g, for the periods from 1 to 21, 22 to 42 and 43 to 56 days of age, respectively. Considering the requirements, prediction models were designed for ME requirements using adjustments for body weight, daily weight gain and temperature. The models predicted the ME requirements for broilers as redult of from breed manual recommendations and the studied models.