摘要
本试验旨在研究褐藻寡糖(AOS)对肉鸡生长性能、免疫器官指数、血清抗氧化指标和肠道健康的影响.试验分别用100、200和800 U的褐藻胶裂解酶PDE9水解褐藻酸钠制备不同分子量的AOS,之后使用高效分子排阻色谱方法测定AOS的重均分子量,得出3种AOS的重均分子量分别为23 981、5 038和3 766 u,依次标记为高分子量、中分子量和低分子量.然后选取体况一致和体重接近的1日龄爱拔益加(AA)雄性肉鸡280只,随机分为4组,每组7个重复,每个重复10只.对照组(CON组)饲喂基础饲粮,试验组分别在基础饲粮中添加200 mg/kg低分子量(AL组)、中分子量(AM组)和高分子量(AH组)的AOS.试验期40 d.结果表明:1)与CON组相比,AL组、AM组和AH组肉鸡40日龄体重均显著提高(P＜0.05),1～40日龄和21～40日龄平均日增重(ADG)均显著提高(P＜0.05);AL组和AM组肉鸡20日龄体重均显著提高(P＜0.05),1～20日龄ADG均显著提高(P＜0.05),1～20日龄料重比(F/G)均显著降低(P＜0.05).2)与CON组相比,AL组肉鸡20日龄肝脏指数显著降低(P＜0.05);AM组和AH组肉鸡20日龄法氏囊指数均显著提高(P＜0.05).3)与CON组相比,AH组肉鸡空肠隐窝深度(CD)有降低趋势(P=0.084),空肠钠-葡萄糖共转运蛋白1(SGLT1)、锌转运蛋白1(ZnTl)、闭锁小带蛋白-1(ZO-1)、黏蛋白2(mucin-2)和闭合蛋白(occludin)的mRNA相对表达量均显著提高(P＜0.05),空肠封闭蛋白-3(claudin-3)的mRNA相对表达量有提高趋势(P=0.081).4)与CON组相比,AH组肉鸡盲肠扁桃体白细胞介素-10(IL-10)、白细胞介素-17(IL-17)和白细胞介素-1β(IL-1β)的mRNA相对量表达均显著降低(P＜0.05).5)与CON组相比,AH组肉鸡盲肠微生物β多样性差异有显著性趋势(P=0.055),且AH组盲肠拟杆菌属、瘤胃球菌科UCG-005、瘤胃梭菌属、考拉杆菌属、帕拉苏特氏菌属、弯曲杆菌属、鸡杆菌属和埃希氏-志贺氏菌属的相对丰度显著提高(P＜0.05).综上所述,饲粮中添加不同分子量AOS均能有效提高肉鸡生长性能;其中,高分子量AOS在制备中所需的酶量更少,生产成本相对更低,且能增强肉鸡免疫功能和改善肠道健康.
Abstract
The aim of this study was to reveal the effects of alginate oligosaccharide(AOS)on growth per-formance,immune organ indices,serum antioxidant indices and intestinal health of broilers.Sodium alginate was hydrolyzed to prepare AOS of different molecular weights with alginate lyase PDE9 at enzyme-activity u-nits of 100,200 and 800 U.The molecular weights of the prepared AOS were determined using high perform-ance molecular exclusion chromatography.The weight-average molecular weights of the three AOS were 23 981,5 038 and 3 766 u,which were sequentially labeled with high molecular weight,medium molecular weight and low molecular weight,respectively.Then a total of 280 male Arbor Acres(AA)broiler chickens of 1-day-old with the same body condition and similar body weight were randomly divided into 4 groups with 7 replicates per group and 10 chickens per replicate.Broilers in the control group(CON group)were fed a basal diet,and the others in experiment groups were fed the basal diet supplemented with 200 mg/kg AOS with low molecular weight(AL group),medium molecular weight(AM group)and high molecular weight(AH group),respectively.The experiment lasted for 40 days.The results showed as follows:1)compared with CON group,the body weight of broilers at 40 days of age and the average daily gain(ADG)during 1 to 40 and 21 to 40 days of age in AL,AM and AH groups were significantly increased(P＜0.05);the body weight of broilers at 20 days of age and ADG during 1 to 20 days of age in AL and AM groups were significantly in-creased(P＜0.05),and the ratio of feed to gain(F/G)during 1 to 20 days of age was significantly decreased(P＜0.05).2)Compared with CON group,the liver index of broilers at 20 days of age in AL group was sig-nificantly decreased(P＜0.05);the bursa of Fabricius index of broilers at 20 days of age in AM and AH groups was significantly increased(P＜0.05).3)Compared with CON group,the crypt depth(CD)in jeju-num of broilers in AH group tended to be decreased(P=0.084),the mRNA relative expression levels of sodi-um-glucose cotransporter 1(SGLT1),zinc transporter 1(ZnT1),zonula occluden-1(ZO-1),mucin-2,oc-cludin in AH group were significantly increased(P＜0.05),and the claudin-3 mRNA relative expression level in jejunum tended to be increased(P=0.081).4)Compared with CON group,the mRNA relative expression levels of interleukin-10(IL-10),interleukin-17(IL-17)and interleukin-1 β(IL-1β)in cecal tonsil of broilers in AH group were significantly decreased(P＜0.05).5)Compared with CON group,the β diversity of micro-biota in cecum of broilers in AH group tended to be increased(P=0.055),and the relative abundances of Bacteroides,Ruminococcaceae_UCG-005,Ruminiclostridium,Phascolarctobacterium,Parasutterella,Campylobacter,Gallibacterium and Escherichia-Shigella in cecum in AH group were significantly increased(P＜0.05).In conclusion,adding different molecular weights of AOS in diets can effectively improve the growth performance of broilers;among them,the high molecular weight AOS requires less enzyme in prepara-tion,has relatively lower production cost,and can enhance immune function and improve intestinal health of broilers.[Chinese Journal of Animal Nutrition,2024,36(4):2331-2343]
基金项目
国家自然科学基金(32372824)
浙江省基础公益研究计划(LGN20C140001)
维普
万方数据