FEATHER RETENTION FORCE IN BROILERS ANTEMORTEM, PERIMORTEM, AND POSTMORTEM AS INFLUENCED BY CARCASS ORIENTATION, ANGLE OF EXTRACTION, AND SLAUGHTER METHOD

Stunning and slaughter trials were conducted to evaluate the influence of carcass orientation (inverted or supine), angle of feather extract ion (parallel or perpendicular to the carcass surface), and slaughter method (exsanguination without or with spinal cord transection) on fea ther retention force (FRF) in commercial broilers sampled ante-, peri- , and post-mortem. The pectoral, sternal, and femoral feather tracts w ere sampled before and after stunning contralaterally, with a maximum indicating force gauge, from broilers suspended on a shackle (inverted ) or laying on a (suspine). For all trials and sample periods FRF was consistently greater in the femoral area (547 to 679 g) than in the pe ctoral area (273 to 391 g), with the sternal feather tract requiring t he least force at 246 to 343 g. Feathers extracted parallel to the car cass resulted in consistently greater FRF (9 to 29%) than feathers ext racted at a perpendicular angle, at all sample periods. Broilers suspe nded on shackles ante-and peri-mortem had higher FRF values (5 to 30%) than those restrained in shackles in a supine position on a table. Ot her parameters resulted in minor and inconsistent alterations in FRF. Electrical stunning, when not followed by bleeding, resulted in small reductions in FRF (up to 7%). Bleeding after stunning without or with spinal cord transection resulted in variable peri-mortem FRF changes ( +7 to -11% and +11 to -11%, respectively). Only in the pectoral feathe r tract was there a significant increase (5 to 6%) in FRF as broilers went from the ante- to peri-mortem state. At 2 and 6 min after stunnin g and initiation of exsanguination, post-mortem FRF was unaffected by carcass orientation for the pectoral and femoral tracts.