Pasture grazing reduces the incidence of hepatic osteodystrophy in meat-type geese: Insights from the liver bone axis.

Hepatic osteodystrophy, a metabolic bone disorder associated with chronic liver disease, is characterized by reduced bone mass and structural deterioration. While the liver-bone axis is increasingly recognized as a critical mediator of systemic inflammation and hepatic pathology, the efficacy of nutritional strategies targeting this pathway remains poorly understood. This study evaluated the protective effects of pasture grazing through perennial ryegrass feeding on hepatic and skeletal health in meat-type geese. Pasture grazing significantly improved liver morphology, and fat accumulation, while markedly lowering serum liver enzymes (ALT, AST; p < 0.01) and elevating immunoglobulin levels (IgA, IgG, IgM). It enhanced the production of short-chain fatty acids, which improved immune function and decreased inflammatory cytokines (IL-6, IL-18), alongside increased anti-inflammatory cytokines (IL-4), antioxidant enzyme activities (superoxide dismutase, catalase; p < 0.05) and reduced oxidative stress markers (MDA, TBARS). Bone health was improved through elevated bone formation markers (BMP2, OPN), reduced bone resorption marker CTX, increased bone volume, connective density, and trabecular bone porosity, with a significant reduction in osteoclast numbers (p < 0.01) as revealed by micro-CT analysis and TRAP staining. Furthermore, hepatic lipid metabolism was optimized via downregulation of PP2Acα, SREBP2, FASN, HMGCR and upregulation of the LCAT-USF1 axis, promoting high-density lipoprotein maturation, as confirmed by Western blotting and immunofluorescence. In conclusion, pasture grazing exerts multifaceted protective effects on the liver and bone by modulating inflammation, oxidative stress, and lipid metabolism through the liver-bone axis, representing a sustainable feeding strategy to reduce hepatic osteodystrophy incidence in meat-type geese while supporting animal health and production performance.