The use of soybean acid oil as energy source in poultry nutrition, has been limited by its uncertain metabolizable energy value. The objective of this work was to determine the effect of bird age and methodology on the metabolizable energy of commercial soybean acid oil. First and second trials were conducted using total collection excreta methodology with chicks of 12 to 20 days old and roosters, respectively. Third trial used the methodology of Sibbald with roosters. The treatments were reference diet and test diet (reference diet containing 10% acid oil). Values of corrected apparent metabolizable energy obtained in the first and second trials were 7,488 kcal kg-1 and 8,610 kcal kg-1 of dry matter basis for chicks and roosters, respectively. Corrected metabolizable energy for roosters (Sibbald method) was 8,195 kcal kg-1 of dry matter. Metabolizable energy determined in experiments with roosters was higher than that determined with chicks. Formulation of diets containing soybean acid oil should consider the differences in energy contribution of soybean acid oil for young or mature birds.
broiler; metabolizable energy; soybean acid oil; roosters
