Submitted to: Journal of Applied Poultry Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 17, 1999
Publication Date: N/A
Interpretive Summary: Commercial broilers may be bruised at any time during production and even up to the time of slaughter. Bruises resulted in nearly 17 percent of the downgraded broiler carcasses in 1997. To minimize bruising requires a clear understanding of when and how the injuries occur. The present study was conducted to investigate the relationship between the age of a bruise (injury age), its visual appearance, and its microscopic characteristics. Visual observations of bruises can be used to estimate the injury age. If a bruise is mostly red in color, it can be assumed that the bruise occurred fairly recently (unloading and stunning). However, if the bruise is mostly purple (red-blue) in color, then it likely occurred before the bird arrived at the plant (injury age between 6 to 12 hours). A green bruise indicates that the injury is much older because the tissue damage has begun to heal (injury age 24 hours or older). Our data indicate that wing bruises were more difficult to "age" than the other carcass parts because of the wide variation in color that normally occurs in wings. Research on poultry bruises has demonstrated that injuries resulting in bruises can not be blamed solely on the catch crew, nor can they be blamed solely on the processing plant condition. However, when these two groups work together, problem areas can be quickly identified and corrected well before they become economically detrimental for the company as a whole.
Commercial broilers may be bruised at any time during production and even up to the time of slaughter, and to minimize bruising requires a clear understanding of when and how injuries occur. To identify when and how broilers are injured, the relationship between the age of a bruise, its visual appearance, and histological characteristics was investigated. Eighteen injury free commercial broilers were separated into 6 groups with 3 broilers per group. Broilers were anesthetized, bruised on the left side of the breast, wing, and drum using minimum force to bruise (4.1 kg) from a contusion apparatus developed and first used by Hamby at the University of Georgia. Broilers were processed 0, 1, 6, 12, or 24 hours after receiving the injury. Objective color measurements (L, a, b) and photographs revealed that as the injury age increased, breast bruises became darker (higher change in L), whereas wing and drum bruises became lighter (lower change in L). Redness and yellowness of breast bruises were not significantly different at any of the injury ages. With increasing injury age, wing bruises became less red and less yellow, and drum bruises became more red and more yellow. Histological tissue samples showed that drum bruises were more severe than breast or wing bruises at all time intervals. For all bruises, maximum change in L and tissue edema occurred in broiler carcasses injured 6 hours before processing.