Salmonella can survive and contaminate food products at all stages of the pig production chain, posing a serious threat to human health. Slaughtering is an important step in controlling contamination in pigs from farms carrying Salmonella. Inadequate cleaning and disinfection in slaughterhouses can lead to Salmonella survival in carcasses and cause cross-contamination. However, studies on Salmonella prevalence in pig carcasses collected from slaughterhouses are limited. Here, we searched 13,697 documents in the database and retained 250 papers for data extraction through screening and exclusion. We then aggregated the effect size analyses to determine Salmonella prevalence in pig carcasses and on slaughterhouse equipment. The analysis showed that the overall Salmonella prevalence in pig carcasses was 10%. This analysis also suggests that feces and splitting machines are critical control points for controlling Salmonella contamination and that production processes and preventive and control measures need to be optimized and strictly implemented to reduce the spread of Salmonella in pig slaughterhouses.
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