Xianggang Cao

Dezhou donkey is a premium indigenous Chinese livestock breed with high economic value for meat, hide and medicinal uses, and growth rate is a core trait determining farming profitability. However, the molecular and metabolic mechanisms underlying divergent growth rates in this breed have not been fully characterized, with no integrated transcriptomic and metabolomic studies reported. Here, 12 age-matched healthy male Dezhou donkeys were assigned to faster-growing (n = 6) and slower-growing (n = 6) groups by average daily gain, followed by plasma transcriptome sequencing and untargeted LC-MS/MS metabolomics. We identified 480 differentially expressed genes, with the slower-growing group enriching in immune/inflammatory/apoptotic pathways, and the faster-growing group in energy metabolism and transmembrane transport. Lipids and lipid-like molecules represented the largest proportion (44.9%) of the differential metabolites; the slower-growing group was enriched in lipid peroxidation and pro-inflammatory mediators, while the faster-growing group was enriched in unsaturated fatty acids and antioxidants. Integrated analysis revealed core pathways (cAMP signaling, arachidonic acid/unsaturated fatty acid biosynthesis) and key candidate genes/metabolites. Our findings clarify that excessive lipid peroxidation and inflammatory imbalance restrict growth, while efficient energy metabolism promotes faster growth, providing theoretical support for genetic improvement and precision nutrition of Dezhou donkeys.

Donkeys (Equus asinus) are economically and ecologically important livestock species whose genetic potential remains underexplored. This review synthesizes recent advances in donkey genomics, tracing their evolutionary history while evaluating current applications in selective breeding, conservation genetics, and agricultural management. By integrating evidence from population genomics, functional genomics, and comparative evolutionary studies, we summarize major genomic discoveries and identify persistent knowledge gaps, with a focus on translating genomic information into practical breeding outcomes. High-quality reference genomes, population resequencing, and ancient DNA analyses have clarified the African origin, global dispersal history, and environmental adaptation of donkeys. Genome-wide approaches, including GWAS, QTL mapping, and multi-omics analyses, have further identified genes and regulatory pathways associated with thermotolerance, metabolism, reproduction, and milk production. Nevertheless, progress is still limited by small sample sizes, variable sequencing depth, and inconsistencies in phenotyping and bioinformatic pipelines, which constrain cross-population comparisons and practical applications. Addressing these challenges through standardized phenotyping, improved data integration, and collaborative research frameworks will lay the groundwork for effective conservation strategies and sustainable genomic breeding of global donkey populations.