Evaluation of effects of electronarcosis stunning on broiler chickens' welfare and meat quality

Abstract

This study aimed to evaluate the electrical parameters during stunning by electronarcosis and their influence on broiler chicken welfare and meat quality. The research was carried out on 500 broilers, divided into 5 treatments with 100 broilers each. After unloading for slaughter, the birds' haematomas and fractures were evaluated. Subsequent to the groups' evaluation and separation, the electrical parameters were adjusted and the broilers were hung and electrically stunned in a water bath at a commercial slaughterhouse. The five different electrical parameters were: T0 = No electrical stunning (Halal); T1 = 95V, 600Hz and 2.4A; T2 = 125V, 1200Hz and 2.88A; T3 = 129V, 1500Hz and 2.88A and T4 = 216V, 1500Hz and 2.88A. Following the slaughter line, the birds were submitted to bleeding, scalding and feather removal. Carcasses were removed from the line and evaluated individually, recording both the carcass sites where haematomas and fractures were found and pH values (pH15min). Carcasses followed the industrial process, and at the end, the breast fillets were removed and stored (4°C) for 24 h for pH, colouration (L*, a* and b*) and water holding capacity analysis. The different electrical parameters used in stunning through the electronarcosis method had a direct influence on the haematoma and fracture levels, since T0 (63.8%) and T2 (61.7%) had high levels of haematomas and T0 (5.8%) a high level of fractures. The parameters of pH, colouration and water holding capacity showed differences between the various treatments used. The method of slaughter without electrical stunning presented the worst rates of these parameters among the evaluated electrical stunning methods.