Exploring the Regulatory Mechanism of Sodium Butyrate on Milk Fat Synthesis in Lactating Goats Fed a High-Concentrate Diet Based on Metabolomics Technology.

This study investigated the effects of sodium butyrate (SB) supplementation on milk fat synthesis in lactating goats fed a high-concentrate (HC) diet. Twelve lactating Saanen goats were randomly allocated into two groups: a control group (HG) fed a HC diet (concentrate-to-forage ratio = 60:40), and a SB-treated group (SG) fed the same basal diet supplemented with 10 g/kg SB. Compared with the HG group, SB supplementation significantly increased milk fat percentage and milk fat yield (P < 0.01). Meanwhile, SB significantly decreased lipopolysaccharide (LPS) concentrations in both jugular and mammary vein plasma (P < 0.05). In addition, SB enhanced mammary antioxidant capacity, as indicated by elevated activities of superoxide dismutase (SOD) (P < 0.01) and total antioxidant capacity (T-AOC) (P < 0.05). Global metabolomic analysis (UPLC MS/MS) of mammary gland tissues identified 558 differential metabolites, of which 50 were significantly altered and mainly enriched in amino acids, benzene derivatives, heterocyclic compounds, and fatty acids. Pathway analysis showed that SB significantly activated the pentose phosphate pathway, glycerophospholipid metabolism, and linolenic acid metabolism. Furthermore, mammary gland triglyceride (TG) content was significantly higher in the SG group than in the HG group (P < 0.05). SB also upregulated the mRNA expression of key lipogenic enzymes, including acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS) (P < 0.05). These findings demonstrate that SB improves mammary gland health and mitigates the adverse effects of HC diets on milk quality by enhancing de novo fatty acid synthesis in the mammary gland of lactating goats.