Determination of Apparent Metabolizable Energy of Soy Oil Sources and their Effects on Broiler Performance

Two experiments were carried out to determine the physicochemical properties of soy oil sources and investigate the effect of their use in broilers diets on growth performance. In the first experiment, fatty acids composition of the experimental oils was determined and then the apparent metabolizable energy (AME) of oils was estimated through two methods, including multiplying the digestibility of the oil by its gross energy value as well as subtracting AME value of the basal diet from diets containing the oils using Leghorn mature roosters. In the second experiment, the effects of four dietary treatments containing 5% of each oil source was studied on the performance of Ross 308 broilers, replicated 5 times, using a completely randomized design. Linoleic acid content turned out to be 51.46% in soybean oil (SO), 11.35% in hydrogenated soybean oil (HSO), 32.53% in recycled soybean oil (RSO) and 40.03% in acidulated soybean oil soap-stock (ASO). The AME of the oils obtained by multiplying method for SO, HSO, RSO and ASO appeared to be 8920, 8733, 8602 and 7836 kcal/kg, respectively. When calculated by subtracting method, the AME of the oils turned out to be 9016, 8794, 8765 and 7906 kcal/kg, respectively, which indicates higher values obtained from the latter method than former one. Moreover, HSO improved feed intake compared with SO (P