Transmission Mechanisms of Antimicrobial Resistance and Antibiotic-Alternative Strategies in Livestock and Poultry Farming from a One Health Perspective

Antimicrobial resistance (AMR) has become a major challenge in global public health, and the irrational use of antimicrobials in livestock and poultry production is an important driver of the environmental dissemination of resistance genes. Resistance genes can spread across hosts among animals, humans, and ecosystems through the food chain and environmental media, a characteristic that aligns closely with the holistic human-animal-environment health perspective emphasized by the One Health concept. Taking Chinese indigenous black pig breeding as the core research carrier, this paper systematically elucidates the transmission mechanisms by which resistance genes undergo horizontal gene transfer mediated by mobile genetic elements, and incorporates field epidemiological data, gut metagenomic evidence and resistance gene monitoring results specific to black pig farms to illustrate AMR prevalence characteristics unique to black pig breeding systems. This paper focuses on the antimicrobial mechanisms of two types of natural antibiotic alternatives—plant essential oils and bacteriocins—and the potential value of their combined application in inhibiting the spread of resistance. In response to current application bottlenecks in natural antibiotic-alternative products, including formulation compatibility and long-term safety, this paper proposes optimization pathways such as deepening research on synergistic mechanisms, using artificial intelligence to discover novel antimicrobial peptides, and establishing intelligent monitoring and early-warning systems for antimicrobial resistance on farms. Research indicates that promoting safe and efficient natural antibiotic-alternative feed additives, combined with refined management of antimicrobial use at the farming stage, can effectively disrupt the transmission chain of resistance. For black pig breeding, such composite intervention strategies can significantly reduce the detection rates of mcr-1, blaCTX-M and other high-risk resistance genes unique to black pig herds and their breeding environments, providing targeted technical support for green breeding of indigenous black pig varieties. This has important theoretical and practical value for implementing actions to reduce veterinary antimicrobial use, advancing the One Health concept, and safeguarding food safety and public health security.