Effects of Two CO₂ Stunning Methods on the Efficacy of Stunning and Blood Stress Indicators of Turkeys under Commercial Processing Conditions

ABSTRACT

The effect of CO₂ gas-stunning methods (G1: 30% CO2 15 sec, 55% CO₂ 40 sec, 70% CO₂ 45 sec; G2: 30% CO₂ 15 sec, 80% CO₂ 85 sec) on the efficacy of stunning, blood stress indicators and meat quality of turkeys were assessed. A total of 375 turkeys (125 heavy males, 125 light males, and 125 light females) were used. After stunning, clinical parameters (posture-loss, wing-flapping, breathing, response to toe-pinching, eye movements, and palpebral, corneal and pupillary reflexes) and glucose, lactate and cortisol levels were assessed. The G2 method showed a higher percentage of correctly stunned birds (81.3 vs. 70.7%) and lower cortisol levels (0.44 vs. 1.22 g/dL). The weight and sex had a significant influence on the behavioral and physiological responses after stunning. The G2 method was found to be acceptable for animal welfare during stunning, based on both the percentage of animals correctly stunned and dead (92% to 100%) and the blood cortisol level after stunning.

KEYWORDS:

• Poultry
• preslaughter handling
• welfare

Acknowledgments

We would like to thank the Animal Production Department, University of Cordoba, who helped with fieldwork. We would also like to thank the Ministry of Education, Culture and Sport, the Ministry of Economy and Competitiveness, the Santander Bank Universities Global Division and ceiA3 for their collaboration.