Impact of stunning method on blood loss in broilers during exsanguination with two different neck cut methods

Authors: OSBORNE, RACHEL - University Of Georgia; Harris, Caitlin; Buhr, Richard - Jeff; KIEPPER, BRIAN - University Of Georgia

Submitted to: Journal of Applied Poultry Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/20/2023
Publication Date: 11/20/2023
Citation: Osborne, R.C., Harris, C.E., Buhr, R.J., Kiepper, B.H. 2023. Impact of stunning method on blood loss in broilers during exsanguination with two different neck cut methods. Journal of Applied Poultry Research. 31(1):100385. p.1-11. https://doi.org/10.1016/j.japr.2023.100385.
DOI: https://doi.org/10.1016/j.japr.2023.100385

Interpretive Summary: Bleedout during slaughter with subsequent blood collection results in blood being redirected from the wastewater stream to rendering, less wastewater treatment needed at the processing plant, and more saleable by-product. There is relatively little current research into the effect of stunning method on blood loss and blood loss rate, particularly on today’s high breast meat- yield broilers. This study aimed to determine the percent of blood loss and rate of blood loss for three stunning methods (Alternation Current [AC] electrocution, Direct Current [DC] electrical stun, and CASK [controlled atmosphere stun/kill using carbon dioxide]) across the two most commonly used neck cut methods (one-sided neck cut [1S] and two-sided neck cut [2S]). Four trials of 120 birds each from separate flocks of male broilers at 43 to 62 days of age were stunned and then bled using 1S or 2S neck cut. Post-neck cut carcass weights were recorded in 15 seconds intervals for 180 seconds. In general, DC stunning resulted in significantly greater blood loss and rates of blood loss than either AC or CASK, while neck cutting method and treatment interactions had limited impact. Upon evisceration, a substantial proportion of residual blood in AC and CASK broiler carcasses was found to be in the viscera. These results highlight the need to closely reevaluate bleed-out and blood collection processes when changing stunning method for broilers.

Technical Abstract: With over 9 billion broilers processed each year in the U.S., blood is a significant by product of poultry processing. An adequate bleed-out during slaughter with subsequent blood collection results in blood being redirected from the wastewater stream to rendering, less wastewater treatment needed at the processing plant, and more saleable by-product. There is relatively little current research into the effect of stunning method on blood loss and blood loss rate, particularly on today’s high breast meat-yield broilers. This study aimed to determine the percent of blood loss and rate of blood loss for three stunning methods (AC electrocution, DC electrical stun, and CASK [controlled atmosphere stun/kill]) across the two most commonly used neck cut methods (one-sided neck cut [1S] and two-sided neck cut [2S]). Four trials of 120 birds each from separate flocks of male broilers at 62 d, 45 d, 43 d, and 43 d of age were stunned and then exsanguinated via 1S or 2S. Post-neck cut, carcass weights were recorded in 15 s intervals for 180 s. In general, DC stunning resulted in significantly greater blood loss and rates of blood loss than either AC or CASK, while exsanguination method and treatment interactions had limited impact. Upon evisceration, a substantial proportion of residual blood in AC and CASK broiler carcasses was found to be in the viscera. These results highlight the need to closely revaluate bleed-out and blood collection processes when changing stunning method in broilers.