Reference | Sanchez2002 (20020)

A total of 300 market-age birds (~6 weeks) were collected. In each of 10 replications, 15 birds from an airchilling facility and 15 birds from an immersion-chilling plant were sampled after chilling. Immersion-chilled birds were obtained from a facility in Missouri, while air-chilled broilers were processed in a facility in Nebraska. The estimation of the sample number was determined according to Hicks (20), with the standard error of previous estimations being used to determine the variability of the population. The facilities used in this project processed from 45,000 to 60,000 birds per day. It was necessary for the number of samples to be sufŽ cient to detect the organism wit the lowest incidence, in this case Salmonella spp., which has been reported to be present at levels below 25% (33, 56). From this information, it was statistically determined that 150 samples from each facility (300 total) was an appropriate sample number for comparative purposes. Whole-carcass immersion-chilled broilers (no trimmed carcasses) were randomly sampled by plant personnel using USDA standards (23, 57), packaged on ice, stored at 4C, and transported to the laboratory to be analyzed the next day. In the immersion chilling facility, broilers were chilled in a three-stage countercurrent immersion chiller for a total time of 85 min. The first stage used water at 17.2C (63F), the second stage used water at 5.6 to 6.7C (42 to 44F), and the third stage used water at -1.1 to 0C (30 to 32F). The chiller also contained approximately40 ppm chlorine. The plant was chosen because it used processing procedures that were equivalent to those used by the air-chilling facility tested with regard to conditions during stunning, scalding, and inside and outside washes. Air-chilled birds were treated for 120 min in an air-chilling room in two stages, with temperatures of -7.7 to -5.5C (18 to 22F) and -4.4 to -1.1C (24 to 30F), respectively. Samples were randomly obtained by our laboratory personnel in accordance with USDA standards, packaged on ice, transported to our laboratory, and held overnight at 48C to mimic conditions of the immersion-chilled samples.

The whole-carcass rinse method recommended by the USDA (57) was used for microbial sampling of the birds. Carcasses were placed into sterile stomacher bags and rinsed with 400 ml of ButterŽ eld’s phosphate diluent for 1 mi with a rocking motion to assure that all interior and exterior surfaces were rinsed.

AST Method: None

Reference explicitly reports AST breakpoints: False

Reference reports using a MIC table: False