Effects of physical restraint and electrical stunning on plasma corticosterone, postmortem metabolism, and quality of broiler breast muscle1

The objective of this study was to determine the effects of physical restraint and electrical stunning on plasma corticosterone, postmortem metabolism, and quality of broiler breast muscle. Before slaughter, a total of 160 Arbor Acres broilers were randomly categorized into 2 replicate pens (80 broilers per pen) and every pen was randomly divided into 4 groups (free struggle, physical restraint, free struggle and electrical stunning, and physical restraint and electrical stunning; n = 20 per group). Glucose, lactate, and corticosterone were determined on blood plasma samples. Pectoralis major were removed after evisceration and used for determination of meat quality, energy metabolism, and calpain activity. In this study, reducing free struggle by physical restraint combined with electrical stunning improved (P < 0.05) meat water holding capacity. Free struggle preslaughter and during bleeding increased (P < 0.05) breast muscle redness, energy metabolism, and autolysis of μ/m-calpain and decreased (P < 0.05) meat shear values. Physical restraint and electrical stunning decreased (P < 0.05) plasma corticosterone level.