Validating an Inside-Outside Bird Washer as an Effective On-line Reprocessing System

Introduction: On-line reprocessing (OLR) systems and inside-outside bird washers (IOBW) are two critical steps in most poultry slaughter processes that are responsible for helping clean the carcasses by removing visible contaminants such as ingesta and feces. By adding an antimicrobial to the IOBW it can replace the existing OLR system.

Purpose: The purpose of this study was to validate the utilization of an IOBW as an OLR system by applying a single use or recycled antimicrobial solution through the IOBW.

Methods: Poultry carcasses (10 per day, 8 days) from three poultry slaughter plants (A, B and C) were categorized as visually clean or contaminated with digestive tract material and in need of reprocessing. For reprocessing, carcasses were passed through an IOBW applying a peroxyoctanoic and peroxyacetic acid mixture (POAA; 30 - 50 ppm, 480 – 620 kPa, 10 – 15 s) as an antimicrobial treatment. Plant A applied a single use antimicrobial solution through the IOBW, while Plants B and C applied a filtered and recycled solution. Bacteria were rinsed (1 min, 400 ml buffered peptone water solution) from clean carcasses collected prior to the IOBW and contaminated carcasses after being reprocessed through the IOBW. Rinsates were analyzed for Escherichia coli, Salmonella, and Campylobacter at Plant A and for E. coli at plants B and C.  Data were analyzed using a 2-sample t-test (counts) or chi-square test (incidence) in Minitab with a significance level of α=0.05.

Results: No fecal material was observed on any of the carcasses sampled after the IOBW. Recovered E. coli, Salmonella, and Campylobacter on reprocessed carcasses were not different (P ≥ 0.05) from those from visually clean carcasses sampled prior to the IOBW applying a single use POAA solution (2.5 ± 0.9 and 2.5 ± 0.9, 0.1 ± 0.5 and 0.2 ± 0.5, and 1.0 ± 1.2 and 1.3 ± 1.1 log CFU/ml, respectively); and the incidence rates were similar (P ≥ 0.05) for Salmonella (96.3 and 98.8%, respectively) and lower (P < 0.05) for Campylobacter (92.5 and 71.3%, respectively). When a recycled solution of POAA was applied through the IOBW, E. coli populations of clean and reprocessed carcasses were different (P < 0.05) but not biologically meaningful (1.9 ± 0.6 log and 2.1 ± 0.7 CFU/ml, respectively).

Significance: These data indicate that an IOBW that applies a single use or recycled solution of POAA can be used for OLR and can eliminate the need for a stand-alone OLR system.