Nutritional and Functional Effects of Ganoderma lucidum-Fermented Mulberry Leaves in Aged Laying Hens

Solid-state fermentation (SSF) can reduce antinutritional factors and improve the nutritional value of plant feed substrates. Here, we characterized mulberry leaves fermented with Ganoderma lucidum and evaluated a 3% dietary inclusion level in aged laying hens. Fermentation increased crude protein by 19.51% and increased total, essential, and branched-chain amino acids. Tannin and phytic acid contents decreased by 31.03% and 19.61%, respectively. After 60 days, the FML group showed a laying rate of 76%, comparable to Con (76%) and UML (74%), and no significant differences were detected in egg quality traits; however, the FML diet significantly reduced egg-yolk cholesterol relative to both Con and UML. Both UML and FML increased serum T-AOC, SOD, and CAT activities and reduced MDA. FML produced greater increases in T-AOC and SOD than UML. UML increased serum IgA, whereas FML increased IgG. Both products reduced serum TC and LDL-C. Thus, G. lucidum-mediated SSF improved the nutritional profile of mulberry leaves and altered selected physiological indices at a 3% dietary inclusion level. Dose–response and mechanistic studies are needed to establish efficacy and practical value. The mechanisms underlying the observed changes in antioxidant status, serum lipid profiles, and immunoglobulin concentrations require further elucidation.