Applied research note: impact of broiler carcass orientation after slaughter on breast meat quality when evaluating delayed processing

Authors: Harris, Caitlin; CHOI, JANGHAN - Orise Fellow; SHAKERI, MAJID - Orise Fellow; KIEPPER, BRIAN - University Of Georgia; Kong, Byungwhi; Buhr, Richard; Zhuang, Hong; Bowker, Brian

Submitted to: Journal of Applied Poultry Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/5/2025
Publication Date: 7/10/2025
Citation: Harris, C.E., Choi, J., Shakeri, M., Kiepper, B.H., Kong, B.C., Buhr, R.J., Zhuang, H., Bowker, B.C. 2025. Applied research note: impact of broiler carcass orientation after slaughter on breast meat quality when evaluating delayed processing. Journal of Applied Poultry Research. 34(3). https://doi.org/10.1016/j.japr.2025.100573.
DOI: https://doi.org/10.1016/j.japr.2025.100573

Interpretive Summary: In the modern U.S. poultry industry at the time of harvest, feed-withdrawn broilers are caught on the farm, loaded into crates, transported to a commercial processing facility, and held in a holding area before slaughter. The concept of poultry on-farm slaughter and transport of carcasses to processing plants has been proposed, as it may mitigate bird welfare and meat quality problems sometimes associated with traditional poultry harvesting. In prior on-farm slaughter experiments, there has been a pattern of the breast fillets having reddish discoloration, thought to be due to gravity causing residual blood in the carcasses, hanging by their shanks, on shackles to pool in the breast muscles. The purpose of this experiment was to determine if holding carcasses in different orientations (hanging by shanks, hanging by neck, or laying on back) during a 4-hour delay period simulating on-farm slaughter would alter the location of breast muscle discoloration. The meat quality of breast fillets from the treatment groups was compared to the meat quality of fillets from broiler carcasses that were processed without a delay period between bleed-out and scalding. Results from this study confirmed that the location of the discoloration on the breast fillets changed depending on the orientation of the carcasses during the delay period. The discoloration scoring results were also supported by the objective color analysis results and the hemorrhaging scores. The results support the conclusion that the location of the discoloration in the breast fillets was influenced by the carcass holding orientation during the 4 h delay.

Technical Abstract: The live transportation and holding of broilers prior to processing may have the potential to cause issues with meat quality. In prior experiments simulating alternative processing procedures, broilers were slaughtered on-farm and bled carcasses were transported to the plant to continue processing. These carcasses exhibited reddish discoloration on the cranial end of the raw breast fillets. Based on these observations, the current experiment tested if holding carcasses by their shanks caused discoloration in the cranial end of the fillets. The objective of this trial was to determine whether carcass orientation (on back, hanging by neck, hanging by shanks) alters breast meat color. At d43, 120 Cobb-500 males were placed into 4 treatments: control (no delay), 4 h delay + held by shanks (4Shanks), 4 h delay + held by neck (4Neck), or 4 h delay + held on back (4Back). All broilers were electrically stunned and bled-out. The control group was immediately hard-scalded and picked, while the delayed processing treatments were all held for 4 h before scalding/picking. Breast fillets were hot-deboned and chilled overnight. All fillets were assessed for petechial hemorrhaging and discoloration (cranial, caudal, and lateral), as well as additional meat quality measurements. Compared to controls, hemorrhaging and discoloration scores were greater for 4Shanks (cranial) (p=0.0134 and p<0.0001 ), respectively), 4Neck (caudal), and 4Back (lateral) (all p<0.0001). Discoloration scores were supported by a* values of raw fillets. These data suggest that the location of discoloration in the breast fillets was influenced by the carcass holding orientation prior to scalding/picking.