Vegetal choline supplementation modulates hepatic metabolism and immune-related transcriptional responses in broilers

Choline is an essential nutrient involved in lipid transport, hepatic metabolism, and methyl-group donation in poultry. Although synthetic choline chloride is widely used in broiler nutrition, natural alternatives have emerged as potential substitutes with additional metabolic benefits. The present study evaluated the effects of synthetic and vegetal-derived choline supplementation on growth performance, biochemical parameters, and hepatic transcriptomic responses in broiler chickens. We compared three dietary treatments: T1-basal: basal diet without supplemental choline; T2-ClCh: basal diet supplemented with synthetic choline chloride; and T3-VegCh: basal diet supplemented with vegetal choline. Productive performance was evaluated throughout the 42d experimental period, while liver transcriptomic analyses were performed at 28 days using RNA sequencing. Differentially expressed genes (DEGs), KEGG pathway enrichment analysis, weighted gene co-expression network analysis (WGCNA), and integrative multivariate analyses were performed. Choline supplementation improved final body weight, average daily gain, and feed conversion ratio during the finisher B phase and over the overall experimental period. Both choline sources reduced total serum lipid concentrations, whereas VegCh additionally reduced alkaline phosphatase activity. Transcriptomic analyses revealed distinct hepatic metabolic profiles between treatments. ClCh supplementation induced a transcriptional program enriched in pro-inflammatory signaling, immune activation, and stress-response pathways, suggesting a metabolically active and inflammatory hepatic state. In contrast, VegCh supplementation enriched pathways associated with glycolysis/gluconeogenesis, the TCA cycle, fatty acid metabolism, PPAR signaling, insulin signaling, mTOR signaling, and glycerolipid metabolism, indicating an anabolic phenotype characterized by lipid biosynthesis and endocrine regulation. Overall, both choline sources improved productive performance; however, VegCh promoted a distinct hepatic transcriptional profile characterized by enrichment in metabolic pathways and reduced activation of immune-related signaling pathways compared with the synthetic source. These findings provide new insights into the molecular effects of dietary choline sources in broiler chickens and support the potential use of plant-derived choline as a functional nutritional strategy to improve metabolic fitness in poultry.