【摘要】 本试验旨在研究丁酸类添加剂及其与合生元(SYN)组合替代杆菌肽锌(BAC-Zn)对肉鸡生长性能和肠道健康的影响。选取1日龄健康罗斯(Ross) 308白羽肉鸡720只(公母各占1/2),随机分为6组,每组6个重复,每个重复20只鸡。对照(NC)组饲喂不含抗生素的玉米-豆粕型基础饲粮,试验组分别在基础饲粮中添加10 mg/kg BAC-Zn(BAC-Zn组)、1 g/kg包膜丁酸钠(CSB)(CSB组)、1 g/kg CSB+0.5 g/kg SYN(CSB+SYN组)、1 g/kg三丁酸甘油酯(GTB)(GTB组)、1 g/kg GTB+0.5 g/kg SYN(GTB+SYN组)。试验期42 d。结果显示:1)与NC和BAC-Zn组相比,饲粮中添加GTB显著降低肉鸡1～21日龄时的料重比(F/G)(P <0.05),添加CSB显著提高22～42日龄时的平均日采食量(ADFI)(P<0.05),添加CSB+SYN或GTB+SYN显著提高1～21日龄时的平均日增重(ADG)(P<0.05),显著降低1～21日龄时的F/G(P<0.05)。2)与BAC-Zn组相比,饲粮中添加CSB、GTB或GTB+SYN显著降低肉鸡空肠食糜中大肠杆菌数量;添加GTB显著提高空肠食糜中乳酸杆菌数量及盲肠食糜中总菌、厚壁菌门、拟杆菌门、梭菌ⅪⅤa、乳酸杆菌数量(P<0.05);添加CSB+SYN显著提高空肠食糜中梭菌ⅪⅤa数量及空肠和盲肠食糜中乳酸杆菌数量(P<0.05);添加GTB+SYN显著提高盲肠食糜中总细菌和乳酸杆菌数量(P<0.05)。3)与NC组相比,饲粮中添加CSB+SYN、GTB或GTB+SYN显著提高肉鸡盲肠食糜中总短链脂肪酸(SCFAs)、乙酸和丙酸浓度(P<0.05)。与BAC-Zn组相比,饲粮中添加GTB+SYN显著提高肉鸡盲肠食糜中总SCFAs和乙酸浓度(P<0.05)。4)与BAC-Zn组相比,饲粮中添加GTB显著提高肉鸡空肠组织连接黏附分子2(JAM2)和盲肠组织白细胞介素-2(IL-2)的mRNA相对表达量(P<0.05),添加GTB+SYN显著提高空肠组织IL-2和闭合小环蛋白-1(ZO-1)以及盲肠组织ZO-1和JAM2的mRNA相对表达量(P<0.05),添加GSB+SYN显著提高盲肠组织黏蛋白2(MUC2)的mRNA相对表达量(P<0.05)。综上所述,CSB和GTB与SYN组合较其单独使用具有更好的促生长效果,GTB较CSB可更好地促进肠道有益菌增殖和SCFAs生成,降低炎症反应,增强肠道屏障,且SYN能增强其益生作用。更多还原

【Abstract】 This study was conducted to investigate the effects of butyric acids additives alone or combination with synbiotics(SYN)to replace bacitracin zinc(BAC-Zn)on growth performance and gut health of broilers.Seven hundred and twenty 1-day-old healthy Ross 308 white-feathered broilers(males and females in half)were randomly divided into 6 groups with 6 replicates per group and 20 broilers per replicate. Broilers in control(NC)group were fed a corn-soybean meal basal diet without antibiotics,and the others in experimental groups were fed the basal diets supplemented with 10 mg/kg BAC-Zn(BAC-Zn group),1 g/kg coated sodium butyrate(CSB,CSB group),1 g/kg CSB+0.5 g/kg SYN(CSB+SYN group),1 g/kg tributyrin(GTB,GTB group)and 1 g/kg GTB+0.5 g/kg SYN(GTB+SYN group). The experiment lasted for 42 days. The results showed as follows:1)compared with groups NC and BAC-Zn,diets supplemented with GTB significantly decreased the ratio of feed to gain(F/G)of broilers at 1 to 21 days of age(P<0.05),diets supplemented with CSB significantly increased average daily feed intake(ADFI)at 22 to 42 days of age(P<0.05),and diets supplemented with CSB+SYN or GTB+SYN significantly increased average daily gain(ADG)and significantly decreased F/G at 1 to 21 days of age(P<0.05). 2)Compared with BAC-Zn group,diets supplemented with CSB,GTB or GTB+SYN significantly decreased the number of Escherichia coli in jejunal chyme of broilers,diets supplemented with GTB significantly increased the numbers of Lactobacillus in jejunal chyme and total bacteria,Firmicutes,Bacteroides,Clostridium clusterⅪⅤa and Lactobacillus in cecal chyme(P<0.05),diets supplemented with CSB+SYN significantly increased the numbers of Clostridium clusterⅪⅤa in jejunal chyme and Lactobacillus in jejunal and cecal chyme(P<0.05),and diets supplemented with GTB+SYN significantly increased the numbers of total bacteria and Lactobacillus in cecal chyme(P<0.05). 3)Compared with NC group,diets supplemented with CSB+SYN,GTB or GTB+SYN significantly increased the concentrations of total short-chain fatty acids(SCFAs),acetic acid and propionic acid in cecal chyme of broilers(P<0.05). Compared with BAC-Zn group,diets supplemented with GTB+SYN significantly increased the concentrations of total SCFAs and acetic acid in cecal chyme of broilers(P < 0. 05). 4)Compared with BAC-Zn group,diets supplemented with GTB significantly increased mRNA relative expression levels of junctional adhesion molecules 2(JAM2)of jejunum and interleukin-2(IL-2)of cecum of broilers(P<0.05),diets supplemented with GTB+SYN significantly increased mRNA relative expression levels of IL-2 and zonula occludens proteins-1(ZO-1)of jejunum and ZO-1 and JAM2 of cecum(P<0.05),and diets supplemented with CSB+SYN significantly increased mRNA relative expression level of mucoprotein 2(MUC2)of cecum(P<0.05). In summary,diets supplemented with CSB and GTB combination with SYN has a better growth-promoting effects than alone supplemented,and GTB has a better effects than CSB on promoting intestinal beneficial bacteria proliferation and SCFAs production,reducing inflammation and enhancing gut barrier,and SYN can enhance their probiotic effects.[Chinese Journal of Animal Nutrition,2020,32(11):5145-5157]更多还原