Effects Of Stunning And Decapitation On Broiler Activity During Bleeding, Blood Loss, Carcass And Breast Meat Quality

By W. D. McNeal, D. L. Fletcher, University of Georgia and R. J. Buhr, USDA's ARS - In today's US poultry processing plants broiler chickens are typically electrically stunned and then bled to cause death while unconscious. However, sometimes the broilers are not adequately stunned or cut and then they could possibly regain consciousness during the bleeding.
calendar icon 2 April 2005
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Interpretive Summary:

Alternatively, if immediately following stunning broilers were decapitated the risk of them regaining consciousness from an insufficient stun, a lengthy stun-to-cut interval, or an inadequate neck cut would be eliminated.

A series of experiments was conducted comparing death by bleeding or decapitation to determine if there were differences in post-stun carcass activity and carcass quality. Carcasses were scored after stunning for activity during bleeding (from no activity to severe flapping and shaking). Carcass quality was determined following defeathering by looking for carcass defects (red wing tips, broken bones, and retained feathers), while meat quality was assessed by measuring meat pH, color, cook loss, and tenderness.

Our results showed that decapitation was very similar to neck bleeding in post-stun carcass activity scores except towards the end of bleeding (after 60 seconds) the decapitated carcasses consistently showed almost no activity. Carcass and muscle quality evaluations were indistinguishable between carcasses that were decapitated or bled. According to the data collected in these experiments, decapitation immediately after stunning, may be an acceptable alternative to bleeding broilers.

Technical Abstract:

Four experiments were conducted to determine the effects of electrical stunning and decapitation on bird activity as well as carcass and meat quality. In Experiment 1, broilers were subjected to one of four stunning and killing methods; no stun and neck cut; stun and neck-cut; no stun and decapitation; and stun and decapitation.

Birds were scored for severity of physical activity on a scale of 1-4 with 1 being no activity and 4 being severe wing flapping and muscular contractions. Carcasses were also scored for red wing tips, and broken bones.

In Experiment 2-4, all birds were stunned prior to neck cut or decapitation. Carcasses were scored as described in Experiment 1 as well as measurements of blood loss, feather removal, and breast meat pH, color, cook loss, and tenderness. Based on carcass activity in Experiment 1, decapitation following stunning was similar to a conventional stun and unilateral neck cut except there was almost no late activity (after 60 s) observed in the decapitated birds.

Decapitation following stunning did not result in any consistent carcass quality defects and was comparable to conventional killing in the four experiments. No differences were found in 24 h lightness values, yellowness, cook yield, tenderness, and ultimate pH, between conventionally killed and decapitated birds. Blood loss and breast meat redness were inconsistent.

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Source: USDA's Agricultural Research Service and University of Georgia - Poultry Science - January 2003

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