EGCG对热应激肉鸡脂肪沉积与肝脏抗氧化性能的影响

Effect of epigallocatechin gallate on lipid deposition and liver anti-oxidative capacity in heat-stressed broilers

为阐明EGCG对热应激肉鸡脂肪沉积与肝脏抗氧化性能的影响,将192只2周龄肉鸡分为4个组别:对照组为适宜温度组(28℃,TN组),饲喂基础日粮,试验组为循环高温组(7:00到19:0035℃,19:00到7:0028℃,HS组),试验组日粮在基础日粮中分别添加0 mg/kg EGCG(HS0组)、300 mg/kg EGCG(HS300组)、600 mg/kg EGCG(HS600组),试验期3周。结果表明,与对照组相比,热应激(HS0组)肉鸡的末重、日增重和日采食量显著降低,肝脏的SOD、GSH-Px活性、Nrf2 mRNA表达水平显著降低(P<0.05),而肝脏中MDA含量、LITAF、NF-κB、FAS、SREBP1 mRNA表达水平以及脂肪沉积显著增加(P<0.05);而热应激肉鸡在饲料中添加EGCG后,上述指标得到明显改善,与热应激组(HS0组)相比,添加EGCG(HS300和HS600)显著增加了肝脏SOD、GSH-Px、CAT活性以及Nrf2 mRNA表达水平(P<0.05),同时肝脏MAD含量、脂肪沉积以及LITAF、NF-κB、FAS、SREBP1 mRNA表达水平,同时改善生产性能。EGCG通过提高肝脏的抗氧化性能,缓解热应激对脂肪沉积及生产性能的影响。

This study aims to investigate the effects of EGCG on the lipid deposition and liver anti-oxidative capacity of broilers under heat stress.One hundred and ninety-two 2-wk-old broilers were divided into four groups with 6 replicates per group and 8 chickens per replicate.One thermoneutral control group(28℃,TN group),which was fed the basal diet;And three cyclic high-temperature groups(35℃ from 7:00 to 19:00;28℃ from 19:00 to 7:00,heat stress(HS)group),which were fed the basal diet with added EGCG at doses of 0 mg/kg(HS0 group),300 mg/kg(HS300 group),and 600 mg/kg(HS600 group),respectively.The growth perfor⁃mance and liver metabolism and lipid deposition indices were performed at 35 d of age.The results showed that heat stress significantly reduced body weight,daily weight gain,daily feed intake,and decreased the activities of superoxide dismutase(SOD)and glutathi⁃one peroxidase(GSH-Px),and the Nrf2 mRNA expression in liver,and increase significantly the levels of malondialdehyde(MDA)and the expression of LITAF,NF-κB,FAS,SREBP1 mRNA and the lipid deposition compared with TN group.EGCG(HS300 and HS600 group)increased the activities of SOD and GSH-Px and catalase(CAT),and increased the Nrf2 mRNA expression,and de⁃creased the MAD contents,and reduced the lipid deposition and expression of LITAF,NF-κB,FAS,SREBP1 mRNA.The results of this study show that EGCG can improve liver antioxidative capacity to alleviate oxidative damage caused by heat stress.