Purpose: This study aimed to evaluate the microbiological contamination in different points of the bovine slaughtering, in order to compare the hygienic profiles from three slaughterhouses located at Minas Gerais State, Brazil.
Methods: Three slaughterhouses (Sl.1, Sl.2, and Sl.3, all inspected by the Brazilian Federal Inspection Service) were selected. From each one, 65 bovine carcasses were sampled by swabbing (400 cm²) in four distinct steps of the slaughtering process (A: bleeding, B: after skinning, C: after evisceration, and D: after last washing). All samples were submitted to analyses to enumerate mesophilic aerobes (Petrifilm™ AC), Enterobacteriaceae (Petrifilm™ EB), coliforms and Escherichia coli (Petrifilm™ EC). The obtained counts (log CFU/cm²) were compared by ANOVA and Tukey (P < 0.05) to verify significant differences between slaughtering steps and slaughterhouses.
Results: A significant decrease of the microbiological counts was observed during the slaughtering process in all three slaughterhouses. Considering the steps A and D, mean counts of mesophilic aerobes ranged from 4.9 to 3.1 log CFU/cm² in Sl.1 (P < 0.05), 3.9 to 3.6 log CFU/cm² in Sl.2 (P > 0.05), and 4.7 to 3.6 log CFU/cm² in Sl.3 (P < 0.05). It was observed significant decrease of the contamination for coliforms and E. coli between steps A and B (P < 0.05), without significant differences between the remaining steps (B, C, and D, P > 0.05), in all slaughterhouses. The same reduction profiles were found for Enterobacteriaceae, except in Sl.2 where no significant differences were observed between all steps (P > 0.05). Sl.1 presented the highest contamination levels of all researched hygiene indicators in step A when compared to Sl.2 and Sl.3, and the end carcasses presented similar levels of contamination in all slaughterhouses.
Significance: The present study demonstrated how the slaughtering steps can contribute to the microbiological contamination of bovine carcasses in three distinct slaughterhouses.