【作者】 李丽；

【导师】 刘福柱；

【作者基本信息】 西北农林科技大学 ， 动物营养与饲料科学， 2012， 硕士

【摘要】 作为生物能源工业的副产品，玉米酒精糟（DDGS，distillers dried grain with solubles）在肉鸡日粮中已经被广泛应用，但DDGS不饱和脂肪酸含量较高，日粮中高水平添加使肌肉易发生氧化变质，对肉鸡机体和肉质的抗氧化特性有负面影响。本研究通过添加一种天然绿色的抗氧化剂——茶多酚（TP，Tea Polyphenols），评估其对高DDGS日粮肉鸡生长性能、肉品质及脂质代谢的影响，探讨解决上述问题的可行性。试验采用单因子完全随机设计，将400只21日龄AA肉鸡随机分为5个处理，每个处理4个重复，每个重复20只。正对照组试验鸡饲喂玉米-豆粕型基础日粮；负对照组饲喂含15%DDGS的玉米-豆粕型基础日粮；试验组在负对照基础日粮中分别添加100、300、500mg/kg的茶多酚。在试验第42d屠宰采样，试验结果如下：1、茶多酚对高DDGS日粮肉鸡生长性能、胴体性能及肉品质的影响（1）肉鸡日粮中添加15%DDGS，对日增重、采食量、料重比、全净膛率、肌肉率无显著影响(P>0.05)。（2）DDGS显著提高了腿肉的剪切力(P<0.05)，提高了肌肉的黄度值(P<0.05)，对肌肉的pH和失水率无显著影响(P>0.05)；添加茶多酚降低了肌肉的剪切力和失水率(P<0.05)。2、茶多酚对高DDGS日粮肉鸡机体及肉质抗氧化性的影响（1）添加15%DDGS显著升高了MDA含量（P<0.05），降低了肉鸡机体和肉质的抗氧化性。（2）本试验条件下，添加500mg/kg TP可以提高肉鸡机体的T-AOC值和GSH-Px水平，显著降低了肌肉的MDA值（P<0.05）。3、茶多酚对高DDGS日粮肉鸡脂质代谢及相关基因mRNA表达的影响（1）本试验条件下，母鸡的腹脂率显著高于公鸡的腹脂率（P<0.01）。（2）添加DDGS和TP对血液TC，TG，HDLC，LDLC水平的影响不显著（P>0.05）；DDGS降低肝脏HL、LPL和LPS酶活性（P>0.05），添加TP后提高了肝脏HL、LPL和LPS酶活性（P>0.05）。（3）DDGS添加后肝脏FAS和LPL基因的表达显著降低（P<0.05），对腹脂基因表达无显著影响（P>0.05）。TP添加后，肝脏FAS基因的表达下降（P<0.05），肝脏LPL基因的表达量升高（P<0.05），茶多酚水平对腹脂合成和分解的影响不同，低水平促进脂肪合成，高水平促进脂肪分解。结论：（1）日粮中添加15%DDGS对肉鸡生产性能无显著负面影响；（2）日粮中添加DDGS可改善肌肉肉色；（3）添加15%DDGS会降低肉鸡机体的抗氧化性能，并使肌肉易于氧化变质、嫩度降低，通过添加茶多酚500mg/kg可以缓解这些负面影响；（4）茶多酚通过抑制肝脏FAS基因的表达降低了脂肪在肝脏中的合成，通过促进LPL基因的表达而提高了脂肪的分解，这两种途径结合起来调节肉鸡机体脂质代谢。更多还原

【Abstract】 Corn distillers dried grains with solubles (DDGS) was widely used in broiler diet as amajor coproduct of bioenergy industry. However, It existed some negative effects of highdietary DDGS on body oxidative resistance and meat quality due to high concentration ofunsaturated fatty acids, resulting in oxdative deterioration and increasing muscle lipidperoxidation. The objective of present research was to investigate the effect of dietary teapolyphenols supplementation on growth performance, antioxidant status, meat quality, lipidmetabolism and related-gene expression of broilers fed high level of DDGS diet. One-factorcompletely random distract design was arranged that a total of400twenty one-day-oldbroiler chicks were randomly assigned to5treatments with4replicates of20birds. Positivecontrol treatment was fed a corn-soybean meal diet, negative control treatment was fed acorn-soybean meal+15%DDGS diet, whereas, experimental treatments were fedcorn-soybean meal+15%DDGS diet supplemented with100，300or500mg/kg of teapolyphenols respectively. The results were showed as follows:1Effects of dietary tea polyphenols on growth performance, carcass traits, meat qualityof broilers fed high level of DDGS diet.1) No significance in daily intake, daily gain, feed efficiency, eviscerated percentage,muscle percentage were observed (P>0.05) when broilers fed15%DDGS diet compared tothat of birds fed corn-soybean meal diet.2) Addition of15%DDGS significantly increased shear force of leg meat (P<0.05),increasing the muscle yellowness(P<0.05), while not significantly effected on pH and waterlossing rate. However, addition of TP in DDGS diet decreased muscle shear force and waterlosing rate (P<0.05).2Effects of tea polyphenols on antioxidant capacity of broilers fed high level of DDGSdiet.1) Addition of15%DDGS significantly increased MDA value (P<0.05)，thus decreasedoxidation resistance of body and meat.2) Addition of500mg/kg TP in high-DDGS diet could improve the level of tissueT-AOC and activity of GSH-Px, significantly decreased the MDA of muscles on broilers.3Effects of tea polyphenols on blood lipid metabolism and mRNA expression of related gene of broilers fed high level of DDGS diets.1) Under this experiment condition, abdominal fat percentage of female broilers wassignificantly higher than that of male broilers(P<0.01).2) DDGS had no significant influence in blood TC, TG, HDLC, LDLC level. DDGSdecreased the liver activity of HL, LPL and LPS, but by addding TP inhanced the liveractivity of HL, LPL and LPS.3) Liver FAS and LPL gene expression were downregulated by DDGS（P<0.05）,however no significant influence on adipose fat tissue gene expression（P>0.05）.Adding TPin diet, the gene of liver FAS expression decreased（P<0.05）, while the gene of liver LPLexpression increased（P<0.05）. Different levels of TP had different effects on abdominal fatsynthesis and decomposition. Low level tend to promote synthesis, and high levels of tend toinhibite decomposition.Conclusion: The results of current reaserch suggested that supplementation of15%DDGS had no significant negative effect on growth performance of broilers, could improvemuscle color, however, it could decrease tenderness and water-holding capacity of muscle.Adding tea polyphenols500mg/kg in high DDGS diet could improve body antioxidantcapacity and meat quality of broilers. Dietary tea polyphenols could restrain the expression ofliver FAS gene to reduce the synthesis of fat in liver, meanwhile, activate expression of LPLgene in abdominal fat tissue to regulate lipidolysis.更多还原