The proliferation of antibiotic resistance genes (ARGs) in livestock manure has raised growing environmental and public health concerns. Composting is widely recognized as an effective method to mitigate ARG dissemination; however, recent studies have increasingly reported a rebound in ARG abundance during the curing stage of composting, undermining its long-term effectiveness. Here, “rebound” refers to a renewed increase in ARG abundance—either in absolute terms or relative to the 16S rRNA gene—following its decline to a minimum during the thermophilic phase. This review systematically summarizes the dynamic changes in ARGs throughout the composting process, with a particular focus on the mechanisms and drivers underlying ARG rebound. Vertical and horizontal gene transfer, along with microbial succession, are discussed as key contributors to this phenomenon. Current strategies to suppress ARG rebound, including microbial community manipulation, hyperthermophilic composting, and exogenous amendments, are evaluated. Furthermore, the roles of heavy metals and extracellular polymeric substances in promoting ARG persistence are examined, highlighting their potential involvement in ARG rebound. This review aims to provide a comprehensive understanding of ARG rebound in composting and to inform the development of more effective, integrated mitigation strategies.

The persistent issue of odor nuisance poses significant challenges to the sustainable development of livestock farming. While previous studies have primarily focused on individual gas concentrations, a comprehensive understanding of overall odor impact based on human perception remains limited. This study introduces a novel perspective by employing the odor activity value (OAV)—calculated from the ratio of gas concentration to its olfactory threshold—to evaluate the actual odor contribution of various compounds. Through a meta-analysis of data from 123 papers, we systematically assessed odor emission characteristics and mitigation strategies across different manure management stages. The results indicated that ammonia (NH₃) (with maximum concentration of 8056 ppm) and hydrogen sulfide (H₂S) (with maximum concentration of 20,057 ppm) were the most concentrated odor components in the whole manure management links. However, considering the olfactory threshold, trimethylamine (TMA) (with OAVmax 380800), H₂S (with OAVmax 48919512), butyric acid (with OAVmax 801684), and aldehydes (with OAVmax 11707) played major odor-causing roles. Notably, biological methods (83%), covering (77%), and additives (39%) were the most efficient odor mitigation strategies in the barn, manure storage, and manure treatment link, respectively. Therefore, employing the OAV-based approach is crucial for identifying priority pollutants and developing targeted control strategies across different livestock species and management stages, ultimately guiding more effective odor mitigation and healthier cohabitation.