The extensive use of antimicrobials in animal farms poses serious safety hazards to both the environment and public health, and this trend is likely to continue. Antimicrobial resistance genes (ARGs) are a class of emerging pollutants that are difficult to remove once introduced. Understanding the environmental transfer of antimicrobial-resistant bacteria (ARB) and ARGs is pivotal for creating control measures. In this review, we summarize the research progress on the spread and detection of ARB and ARG pollution related to animal husbandry. Molecular methods such as high-throughput sequencing have greatly enriched the information about ARB communities. However, it remains challenging to delineate mechanisms regarding ARG induction, transmission, and tempo-spatial changes in the whole process, from animal husbandry to multiple ecosystems. As a result, future research should be more focused on the mechanisms of ARG induction, transmission, and control. We also expect that future research will rely more heavily on metagenomic -analysis, metatranscriptomic sequencing, and multi-omics technologies

Organic fertilizers are rich in nutrients but also frequently contain multiple contaminants that pose a potential threat to the agricultural environment. However, comprehensive investigations into commercial organic fertilizers remain scarce. In this study, 54 commercial organic fertilizer samples—including animal manure-based fertilizers, BOF (bio-organic fertilizer), and other types of fertilizers—were systematically investigated. For OM (organic matter), 48.15% of samples fell below the 30% w/w threshold specified by the industry standard NY/T 525-2021. The exceedance rates of Cu and Zn across all fertilizers were 14.81% and 12.96%, respectively, relative to the German Biowaste Ordinance (BioAbfV) limits. Differences in properties among geographic origins were less pronounced than those among fertilizer types. Pig manure-based fertilizers had the highest nutrient contents, especially phosphorus, but also the highest levels of contaminants, including antibiotics, heavy metals, antibiotic-resistant bacteria (ARB), and antibiotic resistance genes (ARGs). BOF exhibited the best overall quality, with a total nitrogen content 2.0–4.4 times that of the manure-based fertilizers, together with higher organic matter and lower contaminant levels. This study establishes a comprehensive baseline for commercial organic fertilizers in China, providing critical empirical evidence for future industry governance and fertilizer management.