植酸酶对五龙鹅免疫功能和血清生化指标的影响

摘要

为研究在低磷日粮中添加不同水平植酸酶对五龙鹅免疫功能和血清生化指标的影响，将216只1日龄五龙鹅随机分为6组，每组3个重复，每个重复12只，公母各半。Ⅰ组为正对照组（基础日粮，未添加植酸酶），Ⅱ组为负对照组（降低0.1%有效磷水平，未添加植酸酶），Ⅲ～Ⅵ组在负对照组日粮基础上分别添加300、600、900、1200 IU/kg 植酸酶。试验期16周。结果表明：（1）4周龄时，添加900 IU/kg 植酸酶，胸腺指数、法氏囊指数较Ⅰ组显著提高（P ＜0.05），法氏囊指数、胸腺指数和脾脏指数较Ⅱ组显著提高（P ＜0.05或P ＜0.01）；16周龄时，添加900 IU/kg 植酸酶，胸腺指数、脾脏指数较Ⅰ组显著提高（P ＜0.05），胸腺指数、脾脏指数、法氏囊指数较Ⅱ组显著提高（P ＜0.05或P ＜0.01），添加600 IU/kg 植酸酶，胸腺指数和法氏囊指数较Ⅰ组显著提高（P ＜0.05），胸腺指数、脾脏指数和法氏囊指数较Ⅱ组显著提高（P ＜0.05或P ＜0.01）；在免疫后7、14、21、28 d 各植酸酶添加组抗体效价均高于正负对照组，但各处理组间差异不显著（P ＞0.05）。（2）4周龄，植酸酶添加量为900 IU/kg 时，血清钙、磷、谷丙转氨酶与Ⅰ、Ⅱ组均差异显著（P ＜0.05），添加量为600 IU/kg 时，血清磷含量与Ⅰ组差异显著（P ＜0.05），血清磷、尿酸、碱性磷酸酶含量与Ⅱ组差异显著（P ＜0.05）；16周龄，植酸酶添加量为900 IU/kg 时，血清钙、磷、尿酸含量与Ⅰ组差异显著（P ＜0.05），血清钙、磷、尿素氮、尿酸、碱性磷酸酶、谷丙转氨酶均与Ⅱ组差异显著（P ＜0.05或P ＜0.01），添加量为600 IU/kg 时，各血清生化指标均与Ⅰ组差异不显著（P ＞0.05），血清磷和谷丙转氨酶含量均与Ⅱ组差异显著（P ＜0.05）。由此可见，以五龙鹅免疫功能和血清生化指标为判定标准，饲养全期植酸酶适宜添加量为900 IU/kg。%This experiment was conducted to study the effects of phytase on immune performance and serum bio-chemical parameters of Wulong geese. Two hundred and sixteen Wulong geese at 1 day of age were selected and randomly divided into 6 groups with 3 replicates of 12 each,male and female in the equal.GroupⅠwas positive control (basal diet, no phytase),groupⅡwas the negative control(0.1%lower available phosphorus,no phytase),groupⅢ~Ⅵwere supple-mented with 300,600,900,1200 IU/kg phytase in the negative control diets,respectively.The experiment lasted for 16 weeks. The results showed as follows:(1)1 to 4 weeks,compared with group Ⅰ,the supplementation of 900 IU/kg phytase could significantly increase thymus index and bursal index(P<0.05),compared groupⅡ,could significantly increase bursal in-dex,thymus index and spleen index (P<0.05 or P<0.01);5 to 16 weeks,compared with group Ⅰ,the supplementation of 900 IU/kg phytase could significantly increase thymus index and spleen index(P<0.05),compared groupⅡ,could sig-nificantly improve thymus index,spleen index,bursal index(P<0.05 or P<0.01),the supplementation of 600 IU/kg phy-tase,compared with group Ⅰ,could significantly increase thymus index and bursal index(P<0.05),compared with groupⅡ,could significantly improve thymus index,spleen index,bursal index (P < 0.05 or P < 0.01);7,14,21,28 days after immunization,antibody titers of phytase adding group were higher than the negative and positive control group (P < 0.05). (2)1 to 4 weeks,the supplementation of 900 IU/kg phytase,compared with group Ⅰand group Ⅱ,could significantly in-crease Ca,P,Alanine aminotransferase(ALT)in serum(P<0.05),the supplementation of 600 IU/kg phytase,compared with group Ⅰ,could significantly increase P in serum (P <0.05),compared with groupⅡ,could significantly increase P,Uric acid (UN),alkaline phosphatase (AKP)in serum (P < 0.05);5 to 16 weeks,the supplementation of 900 I-U/kg phytase,compared with group Ⅰ,could significantly increase Ca,P,UN in serum (P < 0.05),compared with groupⅡ,could significantly improve P,AKP Ca,Urea nitrogen (BUN),UN,AKP,ALT in serum (P < 0.05 or P < 0.01),the supplementation of 600 IU/kg phytase,compared with groupⅡ,could significantly increase P,ALT in serum (P < 0.05), but the biochemical parameters had no significant difference,compared parameters with group Ⅰ (P > 0.05).In conclu-sion,considerating from the immune performance and serum biochemical parameters,the optimal dietary level of phytase was 900 IU/kg.