NETHERLANDS - New research from Wageningen University shows that broilers can be satisfactorily stunned when they are held in a cone shaped restrainer, followed by head-only stunning, neck-cutting and unconscious shackling.
The process was effective and meat quality from these birds was better than from those stunned in the conventional water bath.
Two experiments were conducted to evaluate a new electrical stunning system for broilers by Bert Lambooij and colleagues at Livestock Research of Wageningen UR.
Their paper, published in Poultry Science, shows that broilers could be restrained in a cone, followed by correct head-only stunning, neck-cutting and unconscious shackling afterward under laboratory and commercial slaughterhouse conditions. When this procedure was used, meat quality was better compared with broilers stunned in the conventional water bath.
The objective of the first experiment was to evaluate the behavioural, neural and physiological responses of 27 broilers after head-only electrical stunning while their bodies were restrained in cone-shaped holders.
In the second experiment, the quality of meat from 30 broilers after head-only electrical stunning in a cone-shaped restrainer was compared with that from 30 broilers stunned in a conventional water bath.
Broilers were restrained in the cone with their heads positioned to facilitate a correct stun, followed by a neck cut by hand.
After stunning, each broiler displayed a tonic phase, followed by minimal brain activity during bleeding. On average, heart rate was 258 ± 51 beats/min before stunning. The heart was observed to malfunction after cutting. According to the correlation dimension analyses, the score remained low. Within a confidence limit of 95%, taking into account the number of birds with a reliable electroencephalogram (n = 27), the chance of an effective stun and exsanguination with all broilers lies between 0.90 and 1.00 using a sinusoidal AC current of 264±29mA (around 130V).
After a brief learning period, operators were able to easily position the broilers in the cone in a commercial setting.
The pH after chilling was 0.5 units lower in the head-only stunned group than the group stunned in a conventional water bath.
After head-only stunning, 60 per cent of breast fillets showed no blood splashes and three per cent showed severe blood splashes compared with 20 and 27 per cent, respectively, after conventional water bath stunning.
No differences in temperature and colour were observed between the two groups. It is concluded that broilers could be restrained in a cone, followed by correct head-only stunning, neck-cutting, and unconscious shackling afterward under laboratory and commercial slaughterhouse conditions. When this procedure was used, meat quality was better compared with broilers stunned in the conventional water bath.
Lambooij E., G.M. Reimert, M.T.W. Verhoeven and V.A. Hindle. 2014. Cone restraining and head-only electrical stunning in broilers: Effects on physiological responses and meat quality. Poultry Science. 93(3):512-518. doi: 10.3382/ps.2013-03318
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