Dissemination of Tylosin Residues in the Poultry Environment: Evaluating Litter and Droppings as Sources of Risk

Introduction: Tylosin, a veterinary antimicrobial belonging to the macrolide family, is commonly used in the poultry industry. Residues generated from its use can be present in the litter and droppings of treated birds. Due to the diverse uses of poultry byproducts, such as fertilizing agricultural soils or incorporation into the diets of other animal species, there is a risk to public health, as the presence of antimicrobial residues favors the development of antimicrobial resistance, which is a global problem. Objective: This study aimed to evaluate the dissemination of tylosin residues from the litter and droppings of treated birds and untreated birds in a controlled broiler environment. Methods: Bird droppings and litter samples were collected and analyzed using HPLC-MS/MS to detect and quantify tylosin residues. Results: The residue concentrations detected in the dropping matrix only exceeded the Limits of Quantification (LOQ = 4 µg kg^-1) in the treated group. The litter matrix had statistically significant differences between the study groups. The persistence of tylosin residues in the litter of birds at day 42 was 290.16 µg kg^-1 in the treated group (A) and 9.35 µg kg^-1 in the adjacent untreated group (B.1). Conclusions: The results indicate that exposure distance influences tylosin residue dissemination.