饲粮胆碱对生长中期草鱼肌肉品质、鳃免疫功能的调控作用及其机制研究

发布时间：2018-03-08 16:37

本文选题：草鱼　切入点：胆碱　出处：《四川农业大学》2015年硕士论文　论文类型：学位论文

【摘要】：初始体重为266.9±0.6 g的草鱼分别饲喂含胆碱水平为197、385、770、1082、1436、1795 mg/kg的饲粮,试验周期为八周,以研究胆碱对草鱼生长性能、肉品质、鳃免疫功能的影响,并最终确定生长中期草鱼的胆碱需要量。结果显示：(1)适宜水平的胆碱显著提高了草鱼的生长性能,提高了草鱼的采食量、饲料效率。(2)适宜水平的胆碱改善了草鱼的肉品质。提高肌肉蛋白质、脂肪以及某些必须氨基酸含量；适宜水平的胆碱显著提高了草鱼肌肉剪切力和胶原蛋白的含量,而降低了肌肉pH值、蒸煮损失以及组织蛋白酶B和L的活力。而且肌肉蒸煮损失的降低可能与胆碱提高了肌肉Cu/Zn-SOD、GPx、GST活力和GSH含量而降低了肌肉氧化损伤有关。(3)草鱼肌肉抗氧化酶活力的提高可能部分上是由于胆碱提高了它们各自的基因转录水平。同时适宜水平的胆碱也提高了草鱼肌肉Nrf2的mRNA水平而降低了Keapla、Keap1b的相对表达水平,并且这种相对表达量的变化可能是引起抗氧化酶mRNA水平改变的原因。(4)适宜水平胆碱的添加也提高了草鱼鳃酸性磷酸酶、溶菌酶的活力,补体C3的含量以及抗菌肽Hepcidin、LEAP2 mRNA的相对表达水平。同时提高了抗炎性细胞因子IL-10、TGFβ1、mRNA的相对表达水平而降低促炎性细胞因子IL-1β、TNFα、IFNγ、IL-8的表达,而且胆碱调节鳃细胞因子的表达可能是由于胆碱提高了TOR、IκB的mRNA水平以及降低了NF-κB、IKKβ、IKKγ的mRNA水平。胆碱也可能通过降低MLCK的表达而提高草鱼鳃occludin/ZO-1、 claudin b、claudin c、claudin 3、claudin 12 mRNA水平,但是胆碱对claudin 15的相对表达水平没有影响。综上所述,适宜水平的饲粮胆碱可以促进草鱼的生长,改善鱼肉品质,提高鳃的免疫屏障功能和物理屏障功能,并可以调控相关信号分子的mRNA水平。本试验以增重百分比(PWG)为标识,确定的草鱼(266.5-787.1 g)饲粮胆碱的需要量为1136.5mg/kg。
[Abstract]:Grass carp with initial body weight of 266.9 卤0.6 g were fed diets with choline level of 1970.385U 77077082N 1436C 1795 mg/kg for eight weeks to study the effects of choline on growth performance, meat quality and Gill immune function of grass carp. The results showed that the appropriate level of choline significantly improved the growth performance and feed intake of grass carp. Feed efficiency. 2) the appropriate level of choline improved the meat quality of grass carp, increased the content of muscle protein, fat and some essential amino acids, and the appropriate level of choline significantly increased the shearing force and collagen content of grass carp muscle. And lower the muscle pH, The loss of cooking and the activity of cathepsin B and L. And the decrease of muscle cooking loss may be related to the increase of muscle CuP / Zn-SODX GST activity and GSH content and the decrease of muscle oxidative damage related to the antioxidant enzyme activity of grass carp muscle. The increase may be due in part to the increased transcription of their respective genes by choline. At the same time, the appropriate level of choline also increased the mRNA level of Nrf2 in grass carp muscle and decreased the relative expression level of Keap1b. The change of relative expression level may be the reason for the change of antioxidant enzyme mRNA level. The addition of appropriate level of choline also increases the activity of acid phosphatase and lysozyme in Gill. The content of complement C3 and the relative expression level of antibacterial peptide LEAP2 mRNA increased the relative expression of IL-10TGF- 尾 1mRNA and decreased the expression of IL-1 尾 -TNF- 伪 -IFN- 纬 -IL-8. Choline regulates the expression of cytokines in Gill probably because choline increases the mRNA level of TORI 魏 B and decreases the mRNA level of Ike 尾 -IKK 纬. Choline may also increase the level of cludin-ZO-1, claudin bclaudin cclaudin 3claudin 12 mRNA by decreasing the expression of MLCK. But choline had no effect on the relative expression of claudin 15. In conclusion, the appropriate dietary choline level could promote the growth of grass carp, improve the quality of fish meat, improve the immune barrier function and physical barrier function of Gill. The dietary choline requirement of grass carp was determined to be 1136.5 mg / kg.
【学位授予单位】：四川农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S965.112

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