Two experiments of metabolism using broilers were carried out to determine the value for apparent metabolizable energy (AME) of soybean oil, the dry matter metabolization coefficient (DMMC), and the nitrogen retention (NR) in the isocaloric rations on two differents ages: growing phase (22 30 days old) and final phase (42 50 days old) and four inclusion levels of soybean oil: 0; 3.3; 6.6 and 9.9%. The experiments lasted eight days, with three days of adaptation period and five days for excreta collection. The energy values of soybean oil were determined by difference. A completely randomized design, with four treatments and four replications with six birds each, was used. The values of AME of soybean oil, NR and DMMC of the diets obtained at levels of 3.3; 6.6; and 9.9% of soybean oil in the growing phase were respectively: 9,437 kcal/kg, 68.22 g, 75.47%; 9,307 kcal/kg, 74.80 g, 74.69% and 8701 kcal/kg, 69.98 g, 74.93% and to final phase: 9,558 kcal/kg, 54.03 g, 79.33%; 8,659 kcal/kg, 48.18 g, 77.92% and 8,307 kcal/kg, 52.88 g, 76.28%. The inclusion levels of soybean oil did showed no effect on AME, NR and DMMC values. Higher values of NR and DMMC were obtained, respectively, for the birds in the growing and final phases. Soybean oil AME of was not affected by ages.
broilers; digestibility; energy value; nitrogen retention; soybean oil
