effect of preslaughter shackling on stress, meat quality traits, and glycolytic potential in broilers

the aim of this study was to investigate the effects of preslaughter shackling durations on some blood parameters, breast and thigh meat quality traits, and muscle metabolites in broilers. the effects of shackling were determined in a group of ross 308 broilers (240 birds) aged 42 days. four shackling treatments were used in experimental tests: shackling of broilers for 10 (group g10; as control), 30 (g30), 60 (g60), and 120 seconds (g120). results showed that corticosterone (cort) level (2314.79 pg ml-1) at 120 seconds shackling group increased (p< 0.01). results indicated that kinase (ck) activity was the highest (2265.69 u i-1) in the 120 seconds shackling group while it was the lowest (1970.64 u i-1) in 10 s group according to the shackling duration (p< 0.05). the breast meat redness value increased due to increase in shackling duration (p< 0.05). it was revealed that shackling duration had decreased breast muscle glycogen level in all treatment groups (p< 0.001). conversely, breast lactate level increased according to increase in shackling duration (p< 0.05). it was revealed that there was a negative relationship (r= -0.466) between breast meat ultimate ph and cooking loss (cl) value in male broilers (p< 0.01). these results indicated that the preslaughter shackling procedure might be a considerably stressful procedure for broilers, particularly exceeding 60 s. this study suggested that broilers could be at disadvantage due to more struggle during long duration shackling and accelerated postmortem glycolysis, which is detrimental to the quality of breast meat.