energy values (aparent metabolizable energy - AME and true metabolizable energy - TME) of soybean meal samples (1, 2, 3, 4, and texturized) and processed full fat soybean samples (Jet Sploder, toasted and micronized) were determined by using the traditional method of excreta collection with growing chickens and the forced feeding method, by using adult cockerels. In the first assay, the experimental diets were fed to four replicates with ten birds in each experimental unit and the basal diet fed to six replicates. In the second assay, each one of feedstuffs was fed to six cockerels, which were fed 15 g at 8:00 A.M. and 15 g at 4:00 P.M., after 24 hours fast. Simultaneously six cockerels were fasted to determine the metabolic and endogenous losses. After the energy values determination, prediction equations were obtained to predict the AMEn with chicks and TMEn with cockerels of soybean and soybean byproducts, based on the feedstuffs chemical composition. The energy values of soybean meals (1, 2, 3, 4, and texturized), full fat soybean Jet Sploder, toasted and micronized were 2337 and 2733; 2376 and 2818; 2469 and 2766; 2437 and 2881; 2833 and 2810; 3224 and 3775; 3400 and 4001; 4104 and 4441 kcal/kg of dry matter, respectively. The equations adjusted with two to four variables showed good predicton of energy values, with R² higher than 92 %. Prediction equations adjusted with crude fiber (CF) and ether extract (EE) variables can be used to predict the energy values of soybean and soybean byproducts being: AMEn = 2822.2 - 90.13FB + 49.96EE (R² = 0,93) and EMVn = 2857.3 - 38.29FB + 61.02EE (R² = .98).
broiler chickens; cockerels; metabolizable energy; prediction equations; processed full fat soybean; soybean meal
