甘草多糖对肉鸡免疫功能的影响

Effect of Glycyrrhiza polysaccharide on immune function of broilers

研究在日粮中添加不同水平甘草多糖(GCP)对肉鸡免疫功能的影响。选用320只1日龄AA肉鸡,随机分成5组,每组4个重复,每个重复16只。对照组饲喂基础日粮,其他4组分别饲喂添加甘草多糖200、500、1000和1500 mg/kg的试验日粮。在21和42日龄时,从每个重复随机抽取4只接近平均体质量的肉鸡,空腹称重,翅静脉采血制备血清,测定血清IgM、IgG、IFN-γ、IL-2、IL-6的质量浓度和新城疫抗体水平;然后处死,摘取免疫器官脾、胸腺、法氏囊并称重,测定免疫器官指数;最后剪取小块脾,用来测定IL-2、IFN-γ、IL-1βmRNA相对表达量。结果显示:500 mg/kg组和1000 mg/kg组的GCP可以显著提高21日龄时肉鸡脾、胸腺和法氏囊指数(P<0.05),1000 mg/kg组和1500 mg/kg组均能显著提高42日龄时肉鸡脾指数(P<0.05);添加GCP能显著提高21日龄时肉鸡血清中Ig M、IL-6、IFN-γ的质量浓度和新城疫抗体水平(P<0.05),并能显著提高42日龄时肉鸡血清中IgM、IL-6和IL-2的质量浓度(P<0.05),其中500 mg/kg组和1000 mg/kg组GCP血清免疫球蛋白和细胞因子质量浓度较高;GCP能显著提高脾IL-2基因mRNA表达水平和21日龄时脾IFN-γ基因mRNA表达水平(P<0.05)。结果表明:在日粮中添加GCP可在一定程度上提高肉鸡的免疫器官指数、新城疫抗体水平及免疫球蛋白质量浓度、细胞因子质量浓度和脾相关细胞因子的基因表达水平,提高机体免疫功能。

To investigate the effects of dietary different levels of Glycyrrhiza polysaccharide(GCP)on immune function of broilers,a total of 320 one-day-old AA broilers were randomly allotted into5 groups with 4 replicates of 16 broilers each.Broilers in the control group were fed a basal diet,while those in the experiment groups were fed the basal diet supplemented with 200 mg/kg,500 mg/kg,1000 mg/kg,and 1500 mg/kg GCP.At 21 and 42 days of age,4 broilers of approximately average weight were randomly selected from each replicate,weighed on an empty stomach,and blood was collected from the wing vein to prepare serum for determination of serum IgM,IgG,IFN-γ,IL-2 and IL-6 mass concentration and antibody level of Newcastle disease;then killed,spleen,thymus and bursa of Fabricius were harvested and weighed to determine the immune organ index;finally a small piece of spleen was cut out and used to determine IL-2,IFN-γ,IL-1βmRNA relative expression level.The results showed that:500 mg/kg group and 1000 mg/kg group significantly increased the spleen,thymus and bursa of Fabricies indexes of broilers at 21 days of age(P<0.05),1000 mg/kg group and 1500 mg/kg group significantly increased the spleen index of broilers at 42 days of age(P<0.05).The addition of GCP can significantly increased serum IgM,IL-6,IFN-γmass concentration and the Newcastle disease antibody level in broiler at 21 days of age(P<0.05),and can increased the serum IgM,IL-6 and IL-2 mass concentration in broiler at 42 days of age(P<0.05).Among them,500 mg/kg group and 1000 mg/kg group had higher levels of GCP serum immunoglobulin and cytokines.GCP can significantly increased the spleen IL-2 gene mRNA expression level and spleen IFN-γgene mRNA expression level at 21 days of age(P<0.05).In conclusion,the addition of GCP to the diet can increase the immune organ index,Newcastle disease antibody levels,immunoglobulin,cytokines and spleen related cytokine gene expression levels of broilers to a certain extent,and improve the body’s immune function.