Investigation of Factors Associated with Leg Trimmings at Processing: A 12-Year Review

Gastrocnemius tendon injury or rupture is a common consequence from various etiologies and conditions in poultry production. The occurrence of tendon injury can cause significant morbidity and lameness in chickens, as well as quality downgrades and increased trimming on carcasses at processing. In this study, 12 yr of data from a poultry processing plant on leg trim only were compiled and analyzed. The association between grower, season, shift, and time were investigated in relation to the prevalence of ruptured tendons and carcass condemnations. A total of 8585 separate data entries from 195 growers were analyzed. Problem flocks were defined as those that had a carcass trimming rate of the percentage change equal to or above the 95th percentile of all data points (0.603%). We identified 430 instances of high trimmings in this study period, involving 90 growers. Of those, eight growers had 10 or more problem flocks in the study period. Overall, there were no differences in trimming rates due to shift; however, problem flocks had a higher trimming rate (percentage) during the night shift. A significantly higher rate of carcass trimmings was noted in the winter months. In problem flocks, a second and lower peak of a higher trimming was also observed in August. There was an upward trending carcass trimming that peaked in 2014, and it trended downward each year through 2020 overall. However, when the problem flocks were excluded, the trimming rate percentage change of trimming decreased slightly from 2008 to 2012 and remained steady through 2020. In conclusion, this study was able to demonstrate noninfectious causes that may be associated with increased leg trimmings and consequently made it possible to narrow down management practices to help decrease the instances of leg trimmings in the processing plant.