Fermented cassava peel with Pleurotus ostreatus as a functional feed: Effects on growth performance, gut health, microbiota, and meat quality in broiler chickens

Background and Aim: The utilization of agro-industrial by-products as alternative feed ingredients has gained increasing attention in poultry production. Cassava peel is abundant but limited by high fiber and anti-nutritional factors. Fermentation using Pleurotus ostreatus can improve its nutritional quality and generate bioactive compounds. This study aimed to evaluate the effects of fermented cassava peel (FCP) on growth performance, carcass traits, immune response, intestinal morphology, microbial population, blood biochemical parameters, and fatty acid profile in broiler chickens. Materials and Methods: A total of broilers were randomly assigned to five dietary treatments: FCP0, FCP5, FCP10, FCP15, and FCP20, representing 0%, 5%, 10%, 15%, and 20% inclusion levels of FCP in the diet. The experiment was conducted over 35 days, including starter and finisher phases. Parameters measured included average daily weight gain (ADWG), average daily feed intake (ADFI), feed conversion ratio (FCR), live body weight (LBW), carcass characteristics, immune organ weights, intestinal villus height (VH), crypt depth (CD), VH/CD ratio, gut microbiota, blood lipid profile, and thigh meat fatty acid composition. Results: Dietary inclusion of FCP significantly improved ADWG and LBW, particularly at the 20% level, without affecting ADFI and FCR. Carcass weight and percentage increased significantly (p < 0.05), while abdominal fat and physiological organs remained unaffected. Thymus weight and percentage were significantly increased, indicating enhanced immune response. Intestinal morphology showed increased VH and VH/CD ratio and decreased CD, reflecting improved absorptive capacity. Microbial analysis revealed reduced Escherichia coli and increased lactic acid bacteria populations. Blood analysis indicated reduced total cholesterol, triglycerides, and low-density lipoprotein, with increased high-density lipoprotein (p < 0.05). Although meat cholesterol was unchanged, FCP improved fatty acid composition by increasing omega-3, omega-6, omega-9, docosahexaenoic acid and eicosapentaenoic acid levels. Conclusion: FCP is an effective functional feed ingredient that enhances growth performance, gut health, immune status, and lipid metabolism in broiler chickens. Inclusion up to 20% can be recommended as a sustainable and economically viable strategy to improve poultry productivity and meat quality. Keywords: antioxidants, broiler chickens, cassava peel fermentation, gut microbiota, Pleurotus ostreatus, poultry nutrition, sustainable feed, β-glucan.