Food Safety Concerns in Free-range Broilers14 May 2013
US - In a study comparing Salmonella and Campylobacter prevalence and concentrations on pasture-raised broilers processed on-farm, in a small USDA-approved slaughter facility and in a mobile processing unit, a high proportion of the carcasses was found to be contaminated. There was one notable exception: no Salmonella were detected on carcasses processed with the mobile unit.
Most pasture-raised broilers processed by three methods were contaminated with Salmonella and/or Campylobacter, according to a baseline study by Walid Q. Ali of the University of Georgia.
In a paper published online in the journal, Food Control, he and co-authors from the University of Arkansas, Oklahoma State University and USDA ARS Russell Research Center report that the small-scale, pasture-raised poultry production model is a growing niche in the locally grown food movement.
Research that focuses on the food safety of small-scale broiler processing methods is limited, they say, so the objective of their study was to compare Salmonella and Campylobacter prevalence and concentrations on pasture-raised broilers processed on-farm, in a small United States Department of Agriculture–Inspected slaughter facility (USDA-IF), and in a Mobile Processing Unit (MPU) pilot plant. A total of 120, 100 and 50 post-chill, pasture-raised broiler carcasses were sampled from each processing method, respectively.
Pathogen prevalence and concentrations from whole carcass rinses were determined using a three-tube Most Probable Number (MPN) method for Salmonella and direct plating method for Campylobacter according to the USDA-Food Safety and Inspection Service (FSIS) protocols.
Both Salmonella prevalence and concentrations on-farm (89 per cent and 1.78 MPN per carcass; 95 per cent CI: 1.60–1.96), USDA-IF (43 per cent and 0.78 MPN per carcass; 95 per cent CI: 0.58–0.98) were significantly (P<0.05) different. Salmonella was not detected on carcasses processed via the MPU.
Campylobacter prevalence was not significantly (P>0.05) different on carcasses processed by the three methods (70 per cent on-farm, 82 per cent USDA-IF and 100 per cent MPU).
The mean log10 Campylobacter concentrations in MPU processed carcasses (5.44 log10 colony-forming units (CFU) per carcass (95 per cent CI: 5.24–5.63) was significantly higher (P<0.05) than on-farm (2.32 log10 CFU per carcass (95 per cent CI: 2.06–2.80) and USDA-IF (2.44 log10 CFU per carcass (95 per cent CI: 2.03–2.85).
Based on the results of this baseline study, most pasture-raised broilers processed by the three methods were contaminated with Salmonella and/or Campylobacter, concluded the paper's co-authors.
They added that further research is needed to assess other potential risk factors such as farm and regional variations that may contribute to the differences in pathogens' prevalence and concentrations.
Trimble L.M., W.Q. Alali, K.E. Gibson, S.C. Ricke, P. Crandall, D. Jaronic and M. Berrang. 2013. Salmonella and Campylobacter prevalence and concentration on pasture-raised broilers processed on-farm, in a Mobile Processing Unit, and at small USDA-inspected facilities. Food Control 34(1):177-182. http://dx.doi.org/10.1016/j.foodcont.2013.04.024
a Center for Food Safety and Department of Food Science and Technology, University of Georgia, Griffin, GA, USAb Center for Food Safety and Department of Food Science, University of Arkansas, Fayetteville, AR, USAc Department of Animal Science, Oklahoma State University, Stillwater, OK, USAd United States Department of Agriculture, Athens, GA, USA
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