In order to determine apparent metabolizable energy and apparent metabolizable energy corrected by nitrogen balance of feed ingredients and to evaluate the effects of this correction on performance of broiler chickens, two experiments were conducted: I) energy determination of corn, soybean meal, meat and bone meal, poultry by-products meal and feather meal by total excreta collection method, using 450 chicks randomly distributed in 30 cages, with 6 treatments and 5 replications; II) performance of 960 broilers, distributed in a completely randomized design, with 5 treatments and 6 replications. Birds that received treatments A (energy matrix from literature) and E (energy without correction adjusted by age) showed better performance with the best feed cost, and treatment E had smaller feed conversion ratio. Therefore, the use of formulations based on metabolizable energy adjusted for age and without correction by nitrogen balance is feasible, both from a zootechnical and economic point of view.
costs; formulation; performance; nutrition; poultry