Meat quality of broiler chickens processed using electrical and controlled atmosphere stunning systems

Authors: RIGGS, MONTANA - Auburn University; HAUCK, RUDIGER - Auburn University; BAKER-COOK, BETHANY - Auburn University; OSBORNE, RACHEL - Auburn University; PAL, AMRIT - Auburn University; BETHONICO TERRA, MARIA - Auburn University; SIMS, GRACIE - Auburn University; URRUTIA, ANDREA - Auburn University; ORELLANA-GALINDO, LETICIA - Auburn University; REINA, MARCO - Auburn University; DEVILLENA, JUAN - Texas Tech University; BOURASSA, DIANNA - Auburn University

Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/6/2022
Publication Date: 12/10/2022
Citation: Riggs, M., Hauck, R., Baker-Cook, B., Osborne, R., Pal, A., Bethonico Terra, M., Sims, G., Urrutia, A., Orellana-Galindo, L., Reina, M., Devillena, J., Bourassa, D. 2022. Meat quality of broiler chickens processed using electrical and controlled atmosphere stunning systems. Poultry Science. https://doi.org/10.1016/j.psj.2022.102422.
DOI: https://doi.org/10.1016/j.psj.2022.102422

Interpretive Summary: As consumers are becoming increasingly concerned with animal welfare, research was conducted to determine the impact of controlled atmosphere stunning (CAS) and electrical stunning (ES) during broiler slaughter. Data from this study indicated that the percentage of carcasses with damaged wings was increased with CAS compared to ES. Differences in breast meat quality between ES and CAS treatments were minimal.

Technical Abstract: Increased consumer concern for animal welfare has led some poultry producers to alter their stunning methods from electrical to controlled atmosphere stunning. The potential for different impacts on meat quality between commercially applied controlled atmosphere stunning (CAS) and electrical stunning (ES) using current US parameters needs further evaluation. Three trials were conducted in a commercial broiler processing facility that uses separate processing lines for ES and CAS. Blood glucose concentrations were measured from broilers stunned by either CAS or ES at: 1) lairage, 2) pre-stunning, and 3) post-stunning, using a glucose monitor. Occurrence of visible wing damage was evaluated post-defeathering and breast fillet meat quality was evaluated through measurement of pH, color, and drip loss at deboning and after 24 h. Data were analyzed using GLM or chi-square with a significance at P = 0.05 and means were separated by Tukey’s HSD. Blood glucose concentrations (mg/dL) from CAS and ES birds were not different at lairage (284, 272, P = 0.2646) or immediately prior to stunning (274, 283, P = 0.6425). Following stunning and neck cut, circulating blood glucose from birds stunned by CAS was higher than ES (418, 259, P < 0.0001). CAS carcasses had more visible wing damage than ES carcasses (3.6%, 2.2%, P < 0.0001). Breast fillet pH was lower, L* was higher, and a* was lower at debone for CAS fillets (5.81, 54.65, 1.96) compared to ES fillets (5.92, 53.15, 2.31, P < 0.0001, P = 0.0005, P = 0.0303). Drip loss did not differ between breast fillets from CAS or ES broilers (4.83, 4.84; P = 0.0859). The implications of increased blood glucose concentration post-CAS are unknown and require further evaluation. However, the increase in visible wing damage observed post-defeathering from CAS carcasses indicated a need for equipment parameter adjustments during the process from stunning through defeathering when using CAS for broiler stunning. Although differences were observed in breast fillet attributes at deboning, these differences would have minimal practical application and were no longer present at 24 h. Overall, use of CAS in a commercial facility resulted in differences in subsequent product quality when compared to ES.