Gorgan University of Agricultural Sciences and Natural Resources Poultry Science Journal 2345-6604 14 1 2026 01 01 Improving Broiler Chicken Intestinal Microbiota and Immune Function Using Black Cumin Seed Bioactive Peptides: A Comparative Study with Prebiotics and Organic Acids 25 34 7354 10.22069/psj.2025.23324.2260 EN Afsaneh Dadashi Oranj Department of Animal Science, University of Mohaghegh Ardabili, Ardabil, Iran Bahman Navidshad Department of Animal Science, University of Mohaghegh Ardabili, Ardabil, Iran Sadegh Karimzadeh Department of Animal Science, Rodaki Higher Education Institute, Tonekabon, Mazandaran, Iran Ali Kalantari Hesari Department of Pathobiology, Faculty of Veterinary Science, Bu-Ali Sina University, Hamedan, Iran Farzad Mirzaei Aghjehgheshlagh Department of Animal Science, University of Mohaghegh Ardabili, Ardabil, Iran Journal Article 2025 02 13 This research investigated the impact of hydrolyzed black cumin seed protein (HBCP) as a potential source of bioactive peptides on the performance of broiler chickens. A total of 560 Ross 308 broiler chicks were randomly assigned to seven distinct dietary groups: Control, 0.05% HBCP, 0.1% HBCP, 0.15% HBCP, 0.2% HBCP, 0.2% Prebiotic and 0.2% Organic Acid. The experiment was conducted over a 42-day period. Birds were fasted for 8 hours before weighing, and feed intake was recorded daily to calculate feed conversion ratios. For microbial and enzyme analyses, two birds per replicate were selected and euthanized, with intestinal samples collected under sterile conditions. Serum samples were taken on day 42 to assess liver enzyme concentrations, and immune response was measured using a sheep red blood cell assay. The results indicated that including 0.1%, 0.15%, and 0.2% HBCP in the broiler diets significantly improved body weight gain and feed conversion ratio throughout the rearing period. Additionally, the inclusion of 0.2% prebiotic and organic acid in the diet notably increased body weight and decreased feed conversion ratio compared to the control group (P<0.05). These dietary interventions had a positive effect on the intestinal microbiota, decreasing Escherichia coli counts while boosting Lactobacillus populations (P<0.05). Additionally, supplementation with HBCP, prebiotics, and organic acids improved immune function, as indicated by elevated antibody titers and enhanced liver enzyme activity. (P<0.05). In conclusion, the study showed that bioactive peptides derived from black cumin hydrolysate had effects similar to those of prebiotics and organic acids, improving both productive traits and immune status in broilers at comparable dosage levels. https://psj.gau.ac.ir/article_7354_1bc0268dd00a386de09ffaecc3adace6.pdf