Impact of stunning method on blood loss in broilers during exsanguination with 2 different neck cut methods

With over 9 billion broilers processed each year in the United States, 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 3 stunning methods (alternating current [AC] electrocution, pulsed direct current [DC] electrical stun, and controlled atmosphere stun/kill [CASK]) across the 2 most commonly used neck cut methods (1-sided neck cut [1S] and 2-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. Postneck 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, whereas 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.