The effects of 2 % inclusion of blue mussel (Mytilus edulis) meal on the performance and clinical welfare of fast-growing broiler chickens

Sustainable feed ingredients are increasingly needed to support environmentally responsible poultry production, particularly those that reduce dependence on conventional protein sources such as soybean meal and fishmeal. Blue mussel meal (BMM) offers potential as a locally produced, circular-economy protein ingredient; however, high and variable mineral content-especially sodium and chloride-has raised concerns regarding its safe dietary inclusion. This study therefore evaluated the effects of a nutritionally balanced diet containing 2 % BMM on broiler chicken performance, physiology, and welfare. A total of 216 Ross 308 broilers were assigned to either a commercial control feed or a diet including 2 % BMM formulated to match the control diet in sodium and chloride content. Live weight, feed intake, water intake, and water‑to‑feed ratio were measured throughout the rearing period. Plasma sodium, chloride, creatinine, and urea were assessed at three ages (13, 21, and 29 days). At 32 days of age, all birds underwent a clinical welfare assessment including gait score, footpad dermatitis, hock burn, cleanliness, vent pasting, and leg deformities. Live weight and feed intake did not differ between treatments (P > 0.20). Water intake showed an interaction between diet and age (P = 0.005), with BMM-fed birds consuming 25.6 ml more water per bird by day 32. Water‑to‑feed ratio tended to be higher in the BMM group (P = 0.051). Plasma sodium and chloride concentrations did not differ between diets, and no elevations in creatinine or urea were observed. Welfare outcomes were comparable between groups, with a tendency for improved gait in BMM-fed birds (P = 0.08) and no cases of footpad dermatitis in either treatment. Overall, the inclusion of 2 % BMM-when formulated to appropriate sodium and chloride levels-did not adversely affect growth, hydration physiology, or welfare. However, further studies must assess these parameters also under full-scale production.