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Submitted to: Meeting Abstract
Publication Type: Proceedings Publication Acceptance Date: 2/11/2000 Publication Date: 2/29/2000 Citation: BUHR, R.J. CONTROLLING CONTAMINATION FROM THE CROP. MEETING ABSTRACT. 2000. Interpretive Summary: Technical Abstract: The attachments that retain the crop in broilers, commercial techniques for removal, and alternatives tested in our pilot plant were presented. Attention has refocused on crop removal to determine the importance of leakage of contents during evisceration on carcass bacterial contamination. Our experiments quantified crop adhesion forces, PPF (peak pull force), and the incidence of crops removed intact following pre-evisceration removal of the head or neck and compared to those eviscerated with the head on. The PPF required to remove the crop intact was similar for carcasses with the head on or off (4.0 and 4.3 kg) but was reduced 13% for those with the neck off (3.6 kg). The incidence of crops removed intact was highest with the neck off (97%), intermediate with the head off (88%), and low with the head on (15%). The reduction in PPF for the neck-off was attributed to removal of crop- neck attachments and increasing the size of the thoracic inlet. Crops that ruptured during evisceration recorded higher PPF than those removed intact. Therefore, crops appear to break due to greater adhesion force, not due to weakness. A second series of experiments evaluated both male and female broilers from 5 to 8-weeks-of-age. PPF and the incidence of crops removed intact was determined during crop extraction that was directed toward the vent or toward the head. PPF was greater for crops removed toward the vent than for those removed toward the head, and greater for males than females. Adjustment for body weight eliminated this difference. The percentage of crops removed intact when pulled toward the head was 98% and 94%, compared to 64 and 70% (for males and females respectively) when pulled toward the vent. |
