日粮添加壳聚糖对蛋种鸡抗氧化功能的影响及其机理研究

发布时间：2018-04-29 06:30

本文选题：壳聚糖 + 蛋种鸡　；参考：《内蒙古农业大学》2017年硕士论文

【摘要】：本论文共分3个试验,研究了壳聚糖对蛋种鸡抗氧化功能的影响及其作用机制。采用单因子完全随机试验设计,将450只产蛋率(92.44%± 0.030)26周龄海兰褐壳种用蛋鸡随机分为1个对照组和4个壳聚糖处理组,每组6个重复,每个重复15只鸡。对照组饲喂基础日粮,不添加壳聚糖,壳聚糖处理组分别在基础日粮中添加250、500、1000、2000 mg/kg的壳聚糖。预试期1周,正试期8周。试验1主要研究壳聚糖对蛋种鸡血清、肝脏和十二指肠组织中抗氧化指标的影响;试验2主要通过研究壳聚糖对蛋种鸡肝脏和十二指肠组织ARA代谢与MAPK信号通路的影响,探讨壳聚糖对蛋种鸡抗氧化功能的作用机制。试验3主要通过研究壳聚糖对蛋种鸡肝脏和十二指肠组织抗氧化酶相关基因及Nrf2基因表达量的影响,从转录水平上进一步探讨壳聚糖对蛋种鸡抗氧化功能影响的分子机理。在本研究条件下,初步得出以下结论:①日粮添加壳聚糖对蛋种鸡血清、肝脏和十二指肠组织中GSH-Px、T-SOD与TrxR活性和抗超氧阴离子能力的影响均存在二次曲线剂量依赖关系。日粮添加250～1000mg/kg的壳聚糖对蛋种鸡血清、肝脏和十二指肠组织中抗氧化功能的促进效果均较好,2000 mg/kg的壳聚糖促进作用减弱,甚至会出现抑制作用。②在试验第8周,随着日粮壳聚糖添加剂量的增加,蛋种鸡肝脏和十二指肠组织JNK与ERK1/2活性呈一次线性升高,而十二指肠组织ARA与LTB4含量、cPLA2活性呈二次曲线升高;并以250～500 mg/kg壳聚糖组的促进作用较强;当2000 mg/kg水平时促进作用减弱。③日粮添加壳聚糖以二次曲线升高模式影响蛋种鸡肝脏和十二指肠组织中GSH-Px、SOD1、SOD2、TrxR1抗氧化酶基因和Nrf2基因表达量;其中,以250～500 mg/kg壳聚糖组较高,2000 mg/kg壳聚糖组则有降低趋势。④壳聚糖对蛋种鸡抗氧化功能影响的可能机制是:壳聚糖通过上调Nrf2基因表达,激活Nrf2信号通路,进而调控下游抗氧化酶的基因表达,增强抗氧化酶活性,促进蛋种鸡的抗氧化功能;壳聚糖通过MAPK信号通路调节十二指肠组织中ARA的释放,减缓机体的氧化应激,保持动物机体良好的代谢状态。⑤综合各项指标得出,蛋种鸡日粮壳聚糖的添加剂量为250～500 mg/kg时具有较强的抗氧化功能。
[Abstract]:In this paper, three experiments were conducted to study the effect of chitosan on antioxidant function and its mechanism of egg breeding chicken. Using a single factor complete random trial design, 450 Hailan brown shell hens at the age of 92.44% 卤0.030 ~ 26 weeks were randomly divided into one control group and four chitosan treatment groups, 6 replicates in each group and 15 chickens in each replica. The control group was fed the basal diet without chitosan. The chitosan treatment group was fed with the basic diet of 250500 ~ 1000 ~ 2 000 mg/kg. The pretest period was 1 week and the positive test period was 8 weeks. In experiment 1, the effects of chitosan on antioxidant indexes in serum, liver and duodenum were studied, and in experiment 2, the effects of chitosan on ARA metabolism and MAPK signaling pathway in liver and duodenum were studied. To explore the mechanism of chitosan on antioxidant function of laying chicken. In experiment 3, the effects of chitosan on the expression of antioxidant enzyme related genes and Nrf2 genes in liver and duodenum of laying hens were studied, and the molecular mechanism of the effects of chitosan on antioxidant function of laying chickens was further studied at the transcriptional level. Under the condition of this study, it was concluded that the effect of adding chitosan on the activity of TrxR and the activity of superoxide anion in serum, liver and duodenum of laying chicken were conic dose-dependent. The effect of chitosan supplemented with 250~1000mg/kg on antioxidant function in serum, liver and duodenum of laying chicken was better. The effect of chitosan in 2000 mg/kg was weakened, and even inhibited by 2. 2 in the 8th week of the experiment. The activities of JNK and ERK1/2 in liver and duodenum of laying hens increased linearly with the increase of dietary chitosan additive content, while the activities of ARA and LTB4 in duodenum tissues increased in quadratic curve. At the level of 2000 mg/kg, the effects of supplementation of chitosan on the liver and duodenum of laying chicken were increased by quadratic curve, and the expression of GSH-PxX SOD1SOD2 and TrxR1 antioxidation enzyme gene and Nrf2 gene in the liver and duodenum of the laying chicken were influenced by the supplementation of chitosan at the level of 2000 mg/kg. The possible mechanism of decreasing the effect of chitosan on antioxidant function of laying chickens was that chitosan could activate Nrf2 signaling pathway by up-regulating the expression of Nrf2 gene. Furthermore, it regulates the gene expression of antioxidant enzymes downstream, enhances the activity of antioxidant enzymes, and promotes the antioxidant function of laying chickens. Chitosan regulates the release of ARA from duodenal tissues through MAPK signaling pathway, thus slowing down the oxidative stress of the body. It was concluded that the additive amount of chitosan in the diet of egg fowl had strong antioxidant function when the dosage of chitosan was 250 ~ 500 mg/kg.
【学位授予单位】：内蒙古农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S831.5

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