SUMMARY The disposal of by-products, such as poultry litter, and carcasses is a serious issue because of risks associated with microbial pathogens, and controlling the pathogen risks requires identifying improved pre-treatment methods capable of inactivating pathogens. As poultry litter and carcasses are known to be major reservoirs of pathogenic microorganisms such as Salmonella and Escherichia coli (E. coli), improvement in existing understanding of the inactivation of these pathogens in poultry litter and carcasses is needed to determine the effective treatment time and temperature. Here we conducted a study to assess the thermal inactivation of 2 common bacteria in poultry productive systems: Escherichia coli (E. coli) and Salmonella enterica (Salmonella). The inactivation study was conducted at 50°C and 60°C using 3 different feedstocks: (1) poultry carcasses, (2) poultry litter, and (3) mixture of poultry litter and carcasses. Each feedstock was inoculated with known concentrations of E. coli and Salmonella prior to thermophilic digestion experiments at 50°C and 60°C. Regardless of feedstock types, E. coli survival was extended beyond 3 d at 50°C. In contrast, Salmonella was no longer detectable within 3 d at 50°C. At 60°C, both E. coli and Salmonella were undetected within an hour. There was no significant difference (at P