Twenty-four Californian rabbits breed with initial body weight of 1.36  ± 0.019 were used in a completely randomized design to evaluate the performance and calculate the net energy contribution of a commercial diet supplemented with foliage of Brosimum alicastrum, as well as the efficiency of utilization of metabolizable energy for maintenance, production and maintenance + production (km, kp and kmp). Animals were fed to cover consumption of 7% of body weight in dry matter. There were four diets: control (commercial feed) and three levels of Brosimum alicastrum inclusion (20, 40 and 60% fodder). Differences were found (P<0.05) in daily weight gain 25.20g, 17.80g, 12.50g, 16.24g and  ±5.44, feed conversion 5.06, 6.85, 7.74 and 9.95± 2.02 and energy conversion (EC) 20.30, 27.92,32.11and42.19  ± 9.12Mcal/kg gain for control diet and 20, 40, and 60% of Brosimum alicastrum inclusion, respectively. Net energy value calculated was1.32Mcal/kg DM for the control dietand0.769Mcal/kg DM for Brosimum alicastrum fodder.