Assessing fat and aquaculture feed recyclable from chicken wastes of poultry slaughterhouse in Bojnoord, North Khorasan Province, Iran

Abstract

The rapid growth of poultry industry has caused large amounts of chicken wastes that must be recycled regarding environmental and economic concerns. This study aimed to assess the fat and aquaculture feed producible from chicken wastes in the Bojnoord poultry slaughterhouse, Iran. The chicken wastes including fatty tissue, viscera, and coccygeal were sampled at three different periods in 2016. Fat samples were analyzed by gas chromatography for determining the fatty acid (FA) profile. The degreased wastes then were used for producing aquaculture feed pellets once in combination with flour and once in mix with poultry by-product meal (PBM). The pellets were tested for physicochemical properties. Averagely, 58.9% of the fatty tissue, 14.5% of the viscera, and 30.4% of the coccygeal were recycled as fat content. Totally, 109368 kg-fat/year was extractable from chicken wastes. The oleic, palmitic, stearic, and palmitoleic represented more than 80% of the total FA content. 67.41% and 67.16% of FA composition was unsaturated and composed of cis-isomers, respectively. The iodine value (IV) and saponification value (SV) were 58.7 g iodine/100 g oil and 156.12 mg KOH/g oil, respectively. The content of moisture, protein, fat, fiber, and ash in the feed composed of degreased chicken wastes and PBM was 7.8, 41.2, 34, 0.9, and 4.4%, respectively. The fat obtained from chicken wastes was suitable for non-edible consumption. Combining degreased wastes with PBM resulted in protein-rich aquaculture feed. This study showed the economic and health benefits of separating components of the poultry slaughterhouse wastes and the possibility of producing aquaculture feed containing suitable micronutrients from these wastes.