This study assessed the impact of Raised Without Antibiotics (RWA) production practices on on-farm antibiotic use, pathogen occurrence, and the prevalence of antimicrobial resistance genes (ARGs) through the whole genome sequencing and analyzing of samples (fecal, manure, sow nasal swab, soil). Some farms that provided antibiotic use data for this study also tested an injection system that automatically records injection events in the barn and its associated meta-data. Based on the results, recommendations for best management practices for various pig production stages were formulated.
Despite encountering technical difficulties, the e-data capture technologies such as the V-ETiC injection system was demonstrated to be a good alternative to recording on paper-based treatment sheets. Compared to non-RWA barns, RWA barns had lower frequency of ARGs and higher frequency of pathogens in piglet feces and in-barn manure samples, both higher ARG and pathogen frequency in sow nasopharynx, and lower frequency of pathogens in sow feces. These results suggest the RWA program is effective in reducing the occurrence of antimicrobial resistance, but may lead to disease outbreaks due to higher pathogen loads, suggesting the need for a long-term surveillance monitoring system of pathogen loads in RWA production systems.
Some of the recommended best management practices to counter the rise of antimicrobial resistance include implementation of appropriate surveillance monitoring and antimicrobial stewardship systems, timely and effective vaccination programs, enhanced disinfection and manure management practices, and improved nutrition and feed programs.
Impact of antibiotic-free production on pathogen occurrence and prevalence of antimicrobial resistance (full article)
