Chinese herbal extracts as feed additives to support male reproductive function in livestock: mechanisms, applications, and research gaps

Reproductive efficiency in male livestock is critical for sustainable production but is frequently compromised by heat stress, cryopreservation, and age-related decline. Chinese herbal extracts—rich in bioactive compounds such as flavonoids, polysaccharides, saponins, and lignans—have emerged as promising natural feed additives. Studies in pigs, goats, and cattle demonstrate improvements in sperm motility, membrane integrity, acrosome integrity, and conception rates. Mechanisms include (1) alleviating oxidative damage via nuclear factor erythroid 2-related factor 2 (Nrf2) activation; (2) suppressing pro-inflammatory signaling through nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK); (3) preserving mitochondrial integrity and energy metabolism; (4) maintaining blood-testis barrier (BTB) structure; and (5) modulating phosphoinositide 3-kinase (PI3K)/ protein kinase B (Akt) and stem cell factor/c-kit (SCF/c-kit) pathways. Overall, Chinese herbal extracts show considerable promise as natural feed additives for improving male reproductive performance in livestock; however, current evidence remains insufficient to support widespread commercial adoption, and further large-scale livestock studies are required to establish efficacy, safety, and economic feasibility.