Evaluation of various levels of walnut meal in broiler diets: effects on growth performance, carcass traits, and thigh meat amino acid and fatty acid composition

BACKGROUND: Replacing conventional feed ingredients with cost-effective and readily available alternatives is a viable strategy for reducing feed costs and enhancing production efficiency. Walnut meal (WM) may serve as a more economical protein source compared to soybean meal. In this study, the effects of incorporating 2.5%, 5.0%, 7.5%, and 10% WM into Ross 308 broiler diets on growth performance, selected slaughter and carcass characteristics, and the fatty acid and amino acid compositions of thigh meat were examined. RESULTS: Adding 10% WM negatively affected (P < 0.05) body weight gain, feed conversion ratio, and carcass weight, while feed intake and some slaughter traits were unaffected. WM increased (P < 0.001) monounsaturated, USFA, n-3 PUFA, and n-6 PUFA levels, while controls had higher (P < 0.001) n-3 PUFA/n-6 PUFA and SFA/USFA ratios. Fatty acid indices indicated health benefits in WM groups. The inclusion of WM in the compound feeds did not affect the amino acid profile of thigh meat. CONCLUSİON: Results showed that including WM at up to 7.5% in broiler diets did not adversely affect growth, carcass traits, or thigh meat fatty acid composition. Dose-response analysis indicated the most favorable outcomes at 2.5% WM. However, when deciding on WM inclusion in broiler (meat-type) diets, the balance between performance and fatty acid composition should be taken into account. © 2026 Society of Chemical Industry.