Supplementation of pomegranate processing waste and waste soybean cooking oil as an alternative feed resource with vitamin E in broiler nutrition: effects on productive performance, meat quality and meat fatty acid composition

This research aimed to determine the effect of dietary supplementation of pomegranate peels powder and waste soybean cooking oil on the performance and meat quality of male Ross 308 broiler chickens. Before start of the experiment, the metabolisable energy of pomegranate peels and other nutritive and chemical contents of pomegranate peels were measured. Also, peroxidation indices and fatty acids profiles of experimental oils were analysed. The experiment was designed as a 3 × 3 × 2 factorial arrangement of treatments including i) pomegranate peels (0, 4 and 8%), ii) waste soybean cooking oil (0, 2 and 4%) and iii) vitamin E (0 and 200 mg/kg diet). Supplementation of 8% pomegranate peels significantly decreased growth performance of broiler chickens (p < 0.05). The supplementation of 4% waste cooking oil significantly reduced body weight gain during the grower and whole experimental period (p < 0.05). Pomegranate peels supplementation decreased peroxide value (PV) and thiobarbituric acid (TBA) and increased pH of meat (p < 0.05). Supplementation of 4% waste cooking oil increased PV and TBA and reduced crude protein, water holding capacity (WHC), and pH of meat (p < 0.05). Vitamin E supplementation significantly decreased TBA and increased WHC of meat (p < 0.05). Supplementation of pomegranate peels decreased saturated fatty acids (SFA) and increased polyunsaturated fatty acids (PUFA) of meat (p < 0.05). Broilers fed diets with 4% waste cooking oil showed higher SFA and lower PUFA contents in meat (p < 0.05). So it can be concluded that 4% pomegranate peels could be used as an alternative feed ingredient and a source of antioxidants in broiler diets, and also 2% waste soybean cooking oil can be included as feed ingredient in broiler diets without adversely affecting performance.