Effects of Rosa roxburghii Tratt. pomace as a functional feed ingredient on the growth performance, antioxidant capacity, meat quality, and muscle chemical composition of broilers

This study aimed to evaluate the effects of dietary supplementation with Rosa roxburghii Tratt. pomace (RRP) as a functional feed ingredient on growth performance, antioxidant capacity, meat quality, and muscle chemical composition in broilers, and to determine the optimal inclusion level through a dose-response approach. A total of 360 one-day-old Arbor Acres broilers were randomly assigned to four treatments with nine replicates of 10 birds each for 42 days: a control group (basal diet) and three groups supplemented with 50, 100, or 150 g/kg RRP, respectively. Results showed that RRP supplementation at 100 or 150 g/kg significantly increased final body weight, average daily gain, and average daily feed intake, while decreasing the feed-to-gain ratio compared with the control (P < 0.05). RRP dose-dependently enhanced superoxide dismutase, glutathione peroxidase, catalase, and total antioxidant capacity activities in both serum and breast muscle, and reduced malondialdehyde content (P < 0.05). Meat quality parameters, including pH, drip loss, shear force, and meat color, were not affected by RRP supplementation. RRP supplementation significantly increased crude protein content and decreased crude fat content in breast muscle (P < 0.05). Regarding detailed chemical composition, RRP supplementation increased total amino acids, total essential amino acids, and the contents of beneficial polyunsaturated fatty acids, while improving the PUFA/SFA ratio and reducing the ω-6/ω-3 ratio. For all significantly affected parameters, the 100 and 150 g/kg groups showed comparable effects, with no significant differences between them. Mortality rate was not affected by any treatment. In conclusion, dietary RRP supplementation at 100 g/kg is recommended as the practical and cost-effective inclusion level to improve growth performance, antioxidant capacity, and muscle nutritional value in broilers, without compromising meat quality. These findings provide a theoretical basis for the application of RRP as a functional feed ingredient, rather than a conventional trace-level additive, in broiler production and support the high-value utilization of agricultural by-products. The relatively high inclusion levels (5-15%) were deliberately chosen to establish a complete dose-response curve and identify both the minimum effective threshold and the safety plateau for this novel by-product.