[目的]探究饲粮添加葛根素对大肠杆菌感染肉鸡生长性能、血液生化指标、抗氧化功能和盲肠微生物菌群的影响.[方法]选取216只1日龄白羽肉仔鸡,随机分为3个处理组,每组6个重复,每个重复12只,公母各半.试验期为42 d.对照组(CON组)和大肠杆菌感染组(EC组)饲喂基础饲粮,大肠杆菌感染+葛根素组(ECPR组)饲喂添加20 mg/kg葛根素的基础饲粮.于10日龄,EC和ECPR组肉鸡灌服1 mL/只大肠杆菌K88悬液(1× 108 CFU/mL),CON组灌服等量的灭菌培养基.于试验第21天采集肉鸡血液,屠宰后采集不同肠段、免疫器官和盲肠食糜,测定血液生化指标、免疫器官指数、血液和肠道抗氧化指标及盲肠微生物数量.[结果]①葛根素对大肠杆菌感染肉鸡各阶段生长性能、免疫器官指数均没有显著影响(P>0.05).②与CON组相比,EC组血浆白蛋白(ALB)、谷丙转氨酶(ALT)、碱性磷酸酶(ALP)、高密度脂蛋白(HDL)和尿酸(UA)的含量/活性显著提高,葡萄糖(GLU)含量显著降低(P<0.05);与EC组相比,ECPR组血浆ALP活性显著降低,钙(Ca)、磷(P)的含量显著升高(P<0.05).③与CON组相比,EC组血浆过氧化氢(H2O2)含量显著升高,十二指肠谷胱甘肽过氧化氢酶(GSH-Px)和过氧化氢酶(CAT)活性、空肠GSH-Px、超氧化物歧化酶(SOD)和诱导型一氧化氮合酶(iNOS)活性及回肠GSH-Px活性显著降低(P<0.05);与EC组相比,ECPR组血浆丙二醛(MDA)和H2O2含量显著降低,十二指肠GSH-Px和CAT活性、空肠GSH-Px和iNOS活性、回肠GSH-Px活性均显著升高(P<0.05).④与CON组相比,EC组盲肠中大肠杆菌数量显著增加(P<0.05).[结论]饲粮中添加20 mg/kg葛根素可通过调节血液生化指标、提高机体抗氧化能力,有效缓解大肠杆菌感染对肉鸡的不利影响.
[Objective]The experiment was conducted to study the effect of puerarin on growth performance,blood biochemical indexes,antioxidant capacity and caecum microflora of broilers challenged with Escherichia coli.[Method]216 healthy 1-day-old White-feathered broilers were randomly divided into 3 groups with 6 replicates in each group and 12 birds in each replicate(6 males and 6 females).The experiment lasted for 42 d.Broilers in control group(CON group)and Escherichia coli challenge group(EC group)were fed basal diet,and the broilers in Escherichia coli challenge+puerarin group(ECPR group)were fed the basal diet supplemented with 20 mg/kg puerarin.At the age of 10 day,broilers in EC and ECPR groups were fed 1 mL Escherichia coli K88 solution(1X108 CFU/mL)per chicken,while chickens in CON group were fed with the same volume of sterilized medium.On the 21st day of the experiment,blood was collected from broiler chickens.After slaughter,different intestinal segments,immune organs,and cecal chyme were collected to measure the blood biochemical indicators,immune organ indexes,blood and intestinal antioxidant indicators,and cecal microbiota of broiler chickens.[Result]①Puerarin had no significant effect on the growth performance and immune organ indexes of broiler challenged with Escherichia coli(P>0.05).②Compared with CON group,the content/activity of plasma albumin(ALB),alanine aminotransferase(ALT),alkaline phosphatase(ALP),high-density lipoprotein(HDL),and uric acid(UA)in EC group were significantly increased,but the content of plasma glucose(GLU)was significantly decreased(P<0.05).Compared with EC group,the plasma ALP activity in ECPR group was significantly decreased,while the plasma contents of calcium(Ca)and phosphorus(P)were significantly increased(P<0.05).③Compared with CON group,plasma hydrogen peroxide(H2O2)content in EC group was significantly increased,whereas the duodenal glutathione peroxidase(GSH-Px)and catalase(CAT)activities,jejunal GSH-Px,superoxide dismutase(SOD)and inducible nitric oxide synthase(iNOS)activities,and ileal GSH-Px activities were significantly decreased(P<0.05).Compared with EC group,plasma malondialdehyde(MDA)and H2O2 contents in ECPR group were significantly decreased,but duodenal GSH-Px and CAT activities,jejunal GSH-Px and iNOS activities,and ileal GSH-Px activity in ECPR group were significantly increased(P<0.05).④Compared with CON group,the content of Escherichia coli in the cecum in EC group was significantly increased(P<0.05).[Conclusion]Dietary supplemented with 20 mg/kg puerarin could effectively mitigate the adverse effects on broiler chickens challenged with Escherichia coli by regulating blood biochemical indexes and improving intestine antioxidant capacity.