Effects of Stunning Methods on the Meat Quality of Yellow-Feathered Broilers

In this work, we compared the effects of carbon dioxide (CO₂) stunning, electric shock and non-stunning (direct slaughter) on the meat quality of yellow-feathered broilers (90 days old). The results showed that the degree of carcass injury in the CO₂ stunning group was the smallest, the rigor mortis process of muscle was shortened, the amount of bleeding was increased, and the rate of pH decline was significantly faster than that in the other two groups (P < 0.05). At 45 min postmortem, the brightness value (L*), redness value (a*) and yellowness value (b*) of the CO₂ stunning group were significantly lower than those of the other two groups (P < 0.05), while a significant increase in L* was found at 24 h (P < 0.05). At 45 min postmortem, the water-holding capacity, tenderness and texture (springiness and chewiness) of the CO₂ stunning group were significantly better than those of the other groups (P < 0.05), whereas the water-holding capacity and texture were significantly poorer at 24 h (P < 0.05). At 24 h, the sensory scores for odor and texture of the electric shock and direct slaughter groups were significantly higher than those of the CO₂ stunning group (P < 0.05). Collectively, CO₂ stunning is not be recommended for the slaughter of yellow-feathered broilers, and It is recommended to further optimize the mode of electric shock.