Submitted to: Southern Poultry Science Society Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: December 9, 2000
Publication Date: August 18, 2000
Citation: BUHR, R.J., CASON JR, J.A., DICKENS, J.A., MARSHALL, D.E. INFLUENCE OF PRE-EVISCERATION CARCASS TRIMMING AND EXTRACTION DIRECTION ON CROP EXTRACTION FORCE AND EFFICIENCY OF CROP REMOVAL DURING MANUAL EVISCERATION OF BROILERS. SOUTHERN POULTRY SCIENCE SOCIETY MEETING ABSTRACT. 2000.
Two experiments were conducted to determine if pre-evisceration carcass trimming (removal of the head or neck) or the direction of crop extraction (pulling through the thoracic inlet or toward the head) would influence the force required for manual crop removal and the incidence of crops removed intact from male broilers (6 wk old). Pre-evisceration trimming consisted of either removing the head between the first and second cervical vertebrae (head-off), or shearing the spinal column parallel with the shoulders (neck-off) without damaging the crop. The esophagus was grasped above the proventriculus for crops pulled through the thoracic inlet or was grasped below the crop within the thoracic inlet for crops pulled toward the head. The peak force required to pull the crop from the carcass was recorded. In the first experiment, the head-off and neck-off techniques resulted in significantly higher rates of crops extracted intact (88.3 and 96.7%, respectively) compared to 15% for the untrimmed head-on carcasses (n=60). The pull force required to remove crops intact from carcasses with the neck off was 16% lower (3.64 kg) than that required for carcasses with the head off (4.34 kg). In the second experiment, crops removed toward the head required 24% less force (2.72 kg) than crops removed through the thoracic inlet (3.60 kg; n=16). Crops pulled toward the head were all removed intact, while only 75% of crops pulled through the thoracic inlet were removed intact. The cervical esophageal connection with the crop, the numerous attachments to the external crop surface, in addition to traversing the thoracic inlet, all appear to influence crop extraction force and the efficiency of intact crop removal.