Optimization of Washing Parameters for Transport Cages Cleaning to Reduce Salmonella Levels in Poultry Slaughterhouses

Transport cages used for live poultry constitute a major source of cross-contamination in slaughterhouses, particularly regarding Salmonella spp. The aim of this study was to evaluate the improvement of washing parameters—specifically temperature and detergent conductivity—in reducing Salmonella contamination as well other microbial parameters in turkey transport cages under industrial conditions. Six washing conditions were tested by combining three temperatures (40, 45, and 60 °C) and different detergent conductivities (0–4 mS/cm), using an alkaline chlorinated detergent. Microbiological analyses included Salmonella spp. and indicators such as mesophilic aerobic bacteria and Enterobacteriaceae, assessed before and after washing at three time points during the processing day. High initial contamination levels were observed in all cases. Results demonstrated a clear synergistic effect between temperature and detergent conductivity. The treatment at 60 °C and 2 mS/cm provided the most effective balance, achieving total elimination of Salmonella and significant reductions in indicator microorganisms without the need for maximum detergent concentration. Increasing conductivity beyond this level did not lead to substantial improvements. These findings support the optimization of washing parameters as a key prerequisite program within HACCP systems in poultry slaughterhouses.