Association study on the regulation of muscle development-related genes, proteins, and metabolites in different tissues by gastrointestinal flora during various developmental stages of Liaoning cashmere goats.

This study aimed to clarify the molecular mechanisms of muscle growth/development in Liaoning cashmere goats and intestinal flora's regulatory role to improve meat production. Muscle tissues (intercostal, hindlimb biceps femoris, longissimus dorsi) and digestive contents (rumen, small intestine, cecum, feces) from goats at 6, 12, 18 months were analyzed via transcriptomics, proteomics, metabolomics, 16S rRNA sequencing, and multi-omics integration. Results: hindlimb biceps femoris optimally developed at 12 months (significantly associated with jejunal g_Lachnospiraceae_NK3A20_group, HOXC10, MYL3, cAMP pathway); longissimus dorsi actively grew at 12 months (closely related to ruminal/cecal g_Christensenellaceae_R-7_group, MEF2A, MYH6; COL1A1/COL1A2 via purine metabolism for fat deposition); intercostal muscle proliferated at 6 months (closely correlated with g_Aeriscardovia, Actin, L-malic acid, l-serine) and GDI was potentially related to its 18-month fat deposition. Multi-omics showed Goat muscle development is coordinately regulated by specific genes, proteins, metabolites, and flora, providing breeding targets for better meat production.