日粮苏氨酸水平对肉鸡生长与生理机能、肠道屏障及其调控机制的影响

发布时间：2018-05-08 10:47

本文选题：苏氨酸 + 肉鸡　；参考：《西北农林科技大学》2017年硕士论文

【摘要】：苏氨酸作为家禽的第三限制性氨基酸,在生产中具有重要作用。试验研究日粮不同苏氨酸水平对肉鸡生长性能、血清生化指标、抗氧化功能、肠道发育、黏膜屏障功能及其分子调控机制的影响,综合评价苏氨酸在家禽生产中的科学利用。试验一:日粮苏氨酸水平对肉鸡生长性能、血清生化和抗氧化功能的影响选取432只体重相近的1日龄健康AA肉鸡,随机分为4组,每组6个重复,每个重复18只鸡,4组分别饲喂苏氨酸水平分别为NRC(1994)标准推荐量的85%、100%、125%和150%的日粮,饲养期为42天。结果表明:(1)日粮不同苏氨酸水平显著影响肉鸡的平均日增重和料重比(P0.05),其中,以100%NRC苏氨酸水平生长性能最佳,但对平均日采食量影响不显著(P0.05);(2)日粮125%NRC苏氨酸处理组能够显著增加肉鸡的脾脏指数、法氏囊指数和胸腺指数(P0.05)。(3)日粮125%、150%NRC苏氨酸水平显著提高肉鸡血清中谷草转氨酶和谷丙转氨酶活性(P0.05);100%NRC苏氨酸水平组肉鸡血清中尿酸的浓度显著低于其他3组(P0.05);日粮中125%NRC苏氨酸水平能够显著增加血清中总蛋白、球蛋白的浓度(P0.05)。(4)日粮苏氨酸水平显著影响肉鸡血清谷胱甘肽过氧化物酶(GSH-Px)及总超氧化物歧化酶(T-SOD)的活性(P0.05),以125%NRC苏氨酸组活性最高;对血清丙二醛(MDA)含量影响不显著(P0.05)。试验二:日粮苏氨酸水平对肉鸡肠道发育、黏膜屏障及其分子调控机制的影响试验设计同试验一。结果表明:(1)日粮添加苏氨酸能显著促进肉鸡小肠组织形态发育(P0.05);(2)日粮不同苏氨酸水平对肉鸡肠道黏膜分泌型免疫球蛋白A(S-IgA)的含量有显著影响(P0.05),表现特征为随着日粮苏氨酸水平升高,S-IgA先升高后降低,其中125%NRC苏氨酸水平处理组肉鸡小肠黏膜S-IgA的含量最高。(3)日粮苏氨酸水平对肉鸡肠道黏蛋白2(MUC2)mRNA的表达量影响显著(P0.05),随着苏氨酸水平的增加,MUC2 mRNA的表达量先升高后降低,以125%NRC苏氨酸水平组表达量最高。(4)日粮苏氨酸水平显著影响21d肉鸡空肠闭合小环蛋白-2(ZO-2)、回肠闭合小环蛋白-1(ZO-1)以及42d空肠ZO-2 mRNA的表达量(P0.05),表现为随着苏氨酸水平增高先降低后升高特征;日粮苏氨酸水平对小肠闭锁蛋白(Occludin)mRNA的表达没有显著影响(P0.05)。日粮添加苏氨酸能显著上调肠道黏膜TOR、S6K1和4E-BP1的mRNA表达量(P0.05),以85%NRC组表达量最低,125%NRC组最高。试验结论:(1)日粮苏氨酸水平显著影响肉鸡ADG和F/G,其中日粮苏氨酸为NRC(1994)推荐的水平时,肉鸡生长性能最佳。但综合肉鸡血清生化和抗氧化功能,日粮苏氨酸达到NRC(1994)125%水平时,其效果最佳。。(2)日粮添加苏氨酸能显著改善肉鸡肠道发育;日粮苏氨酸水平显著影响肉鸡小肠黏膜S-IgA的含量,影响MUC2、肠道紧密连接蛋白以及TOR信号通路相关基因的表达,且以125%NRC苏氨酸处理组效果最好。
[Abstract]:As the third limiting amino acid in poultry, threonine plays an important role in production. The effects of different dietary threonine levels on growth performance, serum biochemical index, antioxidant function, intestinal development, mucosal barrier function and molecular regulation mechanism of broilers were studied, and the scientific utilization of threonine in poultry production was evaluated. Experiment 1: effects of dietary threonine level on growth performance, serum biochemistry and antioxidant function of broilers 432 healthy one-day-old AA broilers of similar body weight were randomly divided into 4 groups with 6 replicates in each group. Each group of 18 chicks were fed a diet of 85 / 100% and 150% of the standard recommended amount of threonine, respectively. The feeding period was 42 days. The results showed that different dietary threonine levels significantly affected the average daily gain (ADG) and feed weight ratio (P0.05N) of broilers, among which 100%NRC threonine level had the best growth performance. However, there was no significant effect on average daily intake (P 0.05). Dietary 125%NRC threonine treatment could significantly increase the spleen index of broilers. The levels of NRC threonine in serum of broilers significantly increased the activities of glutamic oxaloacetic transaminase and alanine aminotransferase in serum of broilers. The serum uric acid concentration of broilers in NRC threonine level group was significantly lower than that in the other three groups (P0.05). The level of 125%NRC threonine significantly increased the total protein in serum. Serum glutathione peroxidase (GSH-Px) and total superoxide dismutase (T-SOD) activity of broilers were significantly affected by the concentration of globulin (P0.05). The activity of 125%NRC threonine group was the highest, but the effect on serum malondialdehyde (MDA) content was not significant (P0.05). Experiment 2: the effects of dietary threonine level on intestinal development, mucosal barrier and its molecular regulatory mechanism in broilers were similar to those in experiment 1. The results showed that the addition of threonine to the diet could significantly promote the development of small intestine tissues in broilers (P0.05). The different levels of threonine had a significant effect on the content of secretory immunoglobulin A S-IgA in the intestinal mucosa of broilers, characterized by the following day. The level of threonine increased firstly and then decreased. The content of S-IgA in intestinal mucosa of broilers treated with 125%NRC threonine level was the highest. The dietary threonine level had a significant effect on the expression of intestinal mucin 2(MUC2)mRNA in broilers. With the increase of threonine level, the expression of MUC2 mRNA increased first and then decreased. Dietary threonine level significantly affected the expression of jejunal closed microcyclic protein -2ZO-2, ileal closed microcyclic protein -1ZO-1 and 42 d jejunum ZO-2 mRNA in broilers on the 21st day after treatment with the highest expression of 125%NRC threonine. The results showed that the level of threonine increased with the increase of threonine level. The characteristic of decreasing first and then rising; Dietary threonine level had no significant effect on the expression of Occludinn mRNA in small intestine atresia. Dietary threonine supplementation significantly upregulated the mRNA expression of TORS6K1 and 4E-BP1 in intestinal mucosa, and the lowest level of TORS6K1 and 4E-BP1 in the 85%NRC group was the highest. Conclusion the dietary threonine level significantly affected ADG and F / G of broilers, and the growth performance of broilers was the best when the dietary threonine level was recommended by NRC 1994). However, when serum biochemistry and antioxidant function of broilers were synthesised, the effect of dietary threonine reached the level of NRC1994 / 125%, the effect was the best. The dietary addition of threonine could significantly improve the intestinal development of broilers, and the dietary threonine level significantly affected the content of S-IgA in intestinal mucosa of broilers. MUC2, intestinal junction protein and TOR signaling pathway related genes were affected, and 125%NRC threonine treatment had the best effect.
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S831.5

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