Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 11, 2000
Publication Date: August 18, 2000
Citation: BUHR, R.J., DICKENS, J.A. INFLUENCE OF GENDER AGE AND DIRECTION OF EXTRACTION ON PEAK PULL FORCE AND THE INCIDENCE OF CROPS REMOVED INTACT FROM BROILERS DURING MANUAL EVISCERATION. POULTRY SCIENCE ASSOCIATION MEETING ABSTRACT. 2000. Technical Abstract: A series of experiments evaluated the influence of gender, age, & the direction of crop extraction on the force required for manual crop removal & the incidence of crops removed intact. Male & female broilers at 5, 6, 7 and 8 wk of age (after a 12-h feed withdrawal period) were weighed, stunned, bled, scalded, & defeathered prior to removal of the crop either through the thoracic inlet or toward the head (n = 16 per gender, age, and treatment). The esophagus was grasped above the proventriculus for crops pulled through the thoracic inlet or below the crop within the thoracic inlet for crops pulled toward the head. Peak pull force to remove the crop increased with age & body weight, & values for males were 22% higher than those for females at all ages. When crop peak pull force was adjusted by individual slaughter weight, no difference due to gender was observed for the four weekly samples. An average of 16% less force was required to pull the crop toward the head than through the thoracic inlet. This difference was present for both male & female broilers for each age sampled. Correlations between slaughter weight & peak pull force were higher for crops pulled through the thoracic inlet (r = 0.85) than for those removed toward the head (r = 0.50). Over the four wk period the incidence of crops removed intact that were pulled through the thoracic cavity was 69% for females and 59% for males, compared to significantly higher incidences of intact crop removal obtained for crops removed toward the head, 90% for females & 97% for males. These results indicate the crop peak pull force was proportional to slaughter weight for both female & male broilers at these four ages.