Xu_2026_J.Sci.Food.Agric__

BACKGROUND: Epigallocatechin gallate (EGCG), the major catechin in green tea, has potent antioxidant, anti-inflammatory, and lipid-regulating effects. Yet its application in growing-finishing pigs remains under-studied. This study tested the dose-dependent effects of dietary EGCG on growth performance, antioxidant capacity, and meat quality in these pigs, hypothesizing activation of the AMPK/PGC-1alpha and Keap1/Nrf2 pathways. Seventy-two healthy DLY pigs (initial body weight 26.42 +/- 0.48 kg) were randomly assigned to four groups (six pens per group; three pigs per pen): control and EGCG-supplemented groups (50, 100, or 200 mg kg(-1)). Diets were fed for 100 days, and outcomes assessed. RESULTS: Results demonstrated that increasing dietary EGCG supplementation significantly reduced the feed-to-gain ratio in both a linear (P = 0.010) and quadratic (P = 0.025) manner, with the minimum value observed at 200 mg kg(-1). At this dosage, EGCG also lowered serum total cholesterol (T-CHO), low-density lipoprotein cholesterol and malondialdehyde concentrations, while elevating immunoglobulin G level (P < 0.05). Dietary supplementation with EGCG significantly increased carcass weight and dressing percentage (P < 0.05). In the longissimus dorsi, EGCG increased redness (a*(24 h)) (P < 0.01) and decreased intramuscular fat, triglyceride, and T-CHO (P < 0.05). In the liver, it downregulated fatty acid synthase (FASN) expression and upregulated the expression of hormone-sensitive triglyceride lipase (HSL) and glucose transporter 4 (GLUT4) expression (P < 0.05). In the same muscle, EGCG upregulated myosin heavy chain I (MyHC I) and downregulated FASN, acetyl-CoA carboxylase (ACC), glucokinase (GCK), and phosphoenolpyruvate carboxykinase (PEPCK) (P < 0.05). Western blotting showed increased P-AMPK and PGC-1alpha protein abundance and decreased Keap1 expression in the longissimus dorsi (P < 0.05); Nrf2 tended to increase. These changes indicate that EGCG enhances meat quality and oxidative stability by activating the AMPK/PGC-1alpha and Keap1/Nrf2 signaling pathways. CONCLUSION: EGCG enhances growth performance and meat quality in finishing pigs by boosting antioxidant capacity, modulating muscle fiber composition, and regulating glucose-lipid metabolism in skeletal muscle and liver. 2026 Society of Chemical Industry.