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Published on: June 18, 2020
Microbial recovery from genetically featherless broiler carcasses after forced cloacal fecal expulsion
J K Northcutt1, W D McNeal, K D Ingram
1USDA, Agricultural Research Service, Athens, GA 30604-5677, USA. jknorth@clemson.edu
Abstract:
A study was conducted to determine external microbiology of genetically featherless broiler carcasses after forced cloacal fecal expulsion. Full-fed featherless broilers were placed into coops, transported, unloaded, shackled, stunned, suffocated, weighed, and divided into 3 treatments groups. Carcasses were transferred to a separate shackle line and passed through a machine designed to induce defecation (squeeze) and then remove external feces (wash). Treatments were obtained by turning the squeezing and washing components on or off. Treatments were as follows: S carcasses were squeezed but not washed; W carcasses were not squeezed but were washed; and SW carcasses were squeezed and washed. Concentrations of total aerobic microorganisms (AB), Escherichia coli (EC), coliforms (CF), and Campylobacter (CPY) recovered from whole carcass rinses did not vary with treatment (P > 0.05). However, counts of Salmonella (SAL) in rinses of S carcasses were 1.4 log(10) cfu/mL greater than counts of SAL found in rinses of SW carcasses (P < 0.05). The SAL prevalence was similar for S (86% positive), W (90% positive), and SW (83% positive) carcasses (P > 0.05). Populations of AB and CF recovered from wash water (water applied in the machine after fecal expulsion) for SW carcasses were significantly higher by 3.1 and 1.5 log(10) cfu/mL, respectively, than the populations of the same bacteria recovered from wash water for W carcasses (P < 0.05). Levels of EC and CPY recovered from wash water did not vary with treatment. There was no difference in CPY and SAL prevalence in water collected after washing W carcasses or SW carcasses (P > 0.05). Data from the present study show that controlled cloacal fecal expulsion followed by carcass washing immediately after slaughter can be used to minimize the numbers of carcass Salmonella and can reduce the likelihood of visible carcass fecal contamination or cross-contamination to other carcasses and processing equipment.
