日粮添加不同水平谷氨酰胺对幼龄獭兔免疫性能及回肠黏蛋白基因表达的影响

Effect of dietary supplementation with different levels of glutamine on immune performance and mucin gene expression in ileum of young rex rabbit

旨在探究日粮添加不同水平的谷氨酰胺对断奶后2个阶段幼龄獭兔免疫器官指数、血清免疫球蛋白(Ig G,Ig A,Ig M)、还原性谷胱甘肽(GSH)含量及回肠黏蛋白基因表达量的影响。选取35日龄断奶獭兔240只,随机分成6组,每组40个重复,每个重复1只獭兔,分别饲喂添加谷氨酰胺0%、0.4%、0.8%、1.2%、1.6%和2.0%的日粮。在正式试验第30天(第I阶段末)和第60天(第II阶段末)时每组随机抽取6只进行采样分析。结果显示日粮添加谷氨酰胺可显著(P<0.05)或极显著(P<0.01)提高I、II 2个阶段幼龄獭兔免疫器官指数、血清Ig A及GSH含量,且具有一定剂量依赖性。对血清Ig M含量影响不显著(P>0.05),Ig G含量极显著降低(P<0.01)。第I阶段对照组回肠黏膜MUC1和MUC2表达量异常高于各试验组,第II阶段MUC1基因的表达量随谷氨酰胺添加量在一定范围内极显著上升(P<0.01),对MUC2无显著影响(P>0.05)。结果表明,日粮添加谷氨酰胺可明显提高幼龄獭兔的免疫性能,增强回肠黏膜免疫力,且不同阶段的幼龄獭兔对谷氨酰胺的需求量有所差异,以应激较强的第I阶段需求较高,为1.6%,第II阶段降至0.8%。

The effect of dietary supplementation with different levels of glutamine on immune organ index, IgG, IgA, IgM,GSH content in serum and mucin gene expression in ileum was examined in rex rabbit in two periods after weaning. A total 240 rex rabbits were random assigned into 6 groups with 40 replicates of 1 rabbit each） and fed a basal diet adding 0,0. 4%,0.8%,1. 2%, 1.6 %,2.0 % glutamine, respectively. Six rabbits in each group were slaughtered on the 30th day and 60th day for sample analyzing. The result showed that adding glutamine in diet could improve the immune organ index and serum IgA and GSH value of young rex rabbit significantly （P〈0.05 or P〈0.01） in both two phases in a dose-dependent manner. However,null association was found in serum IgM content （P〉0.05） while a significantly decreased trend （P〈0.01） was presented in IgG content. The MUC1 and MUC2 gene expression in ileum mucosa of control group were both abnormally increased （P〈0. 01） in phase I. MUC1 increased with glutamine level in a certain range in phase II,while MUC2 expression was not influenced by glutamine （P〉0.05）. In summa- ry,dietary supplementation with glutamine could obviously improve the immune performance of the young rex rabbit and enhance ileal mucosal immunity. Moreover, due to the stronger stress response in the first mouth after weaning, the appropriate diet supplement level of glutamine in phase I is 1.6 G,in phase II is 0. 8 %.