Dietary berberine supplementation regulates production performance, antioxidant capacity, and immunity of Wenchang chicken (Gallus gallus domestics).

Berberine is an isoquinoline alkaloid derived from various medicinal plants, including Coptis chinensis. Berberine exhibits multiple biological activities, including immune modulation, antibacterial activity, and antioxidant properties. Wenchang chicken is a local breed from Hainan Province, China, which is still primarily raised under free-range conditions. In this study, we compared the effects of dietary berberine supplementation on body measurements, weight, meat quality, serum immunoglobulin levels, antioxidant indices, liver transcriptome, proteome, and phosphoproteome in Wenchang chickens. Berberine had no significant effect on the body measurements and weights of Wenchang chickens. However, it significantly altered the color of the breast muscles and significantly reduced the shear force of the breast and leg muscles. Berberine also significantly increased serum Immunoglobulin A(IgA) and Immunoglobulin M(IgM) concentrations and glutathione (GSH) activity in Wenchang chickens, while significantly decreasing malondialdehyde (MDA) concentration. RNA-seq identified 764 differentially expressed genes (DEGs) in the liver. The significantly enriched GO terms were related to immune and inflammatory processes, such as cell chemotaxis, granulocyte migration, and chemotaxis. GSEA identified 50 gene sets, many of which were associated with immune regulation and inflammatory responses, such as Hedgehog signaling, interferon alpha response, and IL-6 JAK-STAT3 signaling. Liver proteomics identified 530 differentially abundant proteins (DAPs), some of which were associated with innate immune responses, such as mitochondrial antiviral signaling protein (MAVS), TNF receptor-associated factor 3 (TRAF3), and BH3-interacting domain death agonist (BID) in the Herpes simplex virus 1 infection pathway. Joint analysis of transcriptome and proteome revealed a highly significant positive correlation between mRNA expression and protein abundance in the liver. A total of 3,482 phosphorylated proteins containing 39,142 phosphorylation sites were identified in Wenchang chicken livers. Among these, 2,086 phosphorylation sites in 714 phosphorylated proteins were significantly upregulated, whereas 2,426 phosphorylation sites in 659 phosphorylated proteins were significantly downregulated in the livers of berberine-treated Wenchang chickens. These phosphoproteins were significantly enriched in KEGG pathways associated with defense, immune signaling regulation, and apoptosis, such as the mTOR signaling pathway, Salmonella infection, and autophagy. This study provided foundational data for the application of berberine in broiler production.