Evaluation of potential disinfectants for preslaughter broiler crop decontamination

The broiler crop has recently been implicated as a major source of Salmonella contamination at commercial processing. Furthermore, feed withdrawal has been positively correlated with increased Salmonella incidence in the crop, probably due to coprophagy. In the present study, a rapid screening assay was developed to evaluate several potential disinfectants in the presence of large quantities of organic matter, simulating the crop environment. An apparent synergistic combination of d-Limonene (DL) and citric acid (CA) was observed when evaluating the potential to eliminate Salmonella in the presence of organic material. A method of encapsulation of DL and CA was developed for voluntary consumption by broilers during feed withdrawal. During an 8-h feed withdrawal individual 8-wk-old broilers voluntarily consumed an average of 21.5 capsules (total of 3.44 g material). When eight capsules were force-administered to Salmonella-challenged 8-wk-old broilers during an abbreviated 4 h feed withdrawal, Salmonella was not recovered using selective enrichment. To evaluate the effect of voluntary capsule consumption, 8-wk-old broilers were challenged with 1 x 108 cfu of Salmonella 5 d prior to an 8 h feed withdrawal. When these broilers were allowed unlimited continuous access to capsules containing DL/CA during an 8 h feed withdrawal, 24.8 capsules per broiler were ingested without affecting Salmonella recovery from crops. When access to capsules containing DL/CA was limited to the final 45 min of an 8 h feed withdrawal in a similar experiment, an average of 22.2 capsules were consumed by each broiler, resulting in a significant decrease in the number of Salmonella-positive crops. Although a number of practical questions and considerations remain, these data suggest that appropriate disinfectants could be administered during preslaughter feed withdrawal for the purpose of reducing foodborne pathogens in crops.