葛根提取物对产气荚膜梭菌感染肉鸡生长性能和肠道屏障功能的影响

Effect of Pueraria Extract on Growth Performance and Intestinal Barrier Function in Broilers Challenged with Clostridium perfringens

试验旨在研究葛根提取物(Pueraria Extract,PE)对产气荚膜梭菌(Clostridium perfringens,CP)感染肉鸡的生长性能和肠道组织形态及屏障功能的影响。采用2×2双因素设计,将264只1日龄健康雌性科宝肉鸡随机分为4组,每个处理6个重复,每个重复11羽。试验全期,对照组和CP组肉鸡饲喂基础饲粮,PE组和PE+CP组在基础饲粮中添加400mg/kgPE,CP组和PE+CP组肉鸡在18~23日龄每天每只灌服1×10^(8)CFU的A型CP,对照组和PE组肉鸡灌服不含产气荚膜梭菌的灭菌培养基。试验期30d。结果表明:与对照组相比,添加PE降低了1~17日龄肉鸡的平均日采食量(P<0.05),与CP组相比,添加PE抑制了18~23日龄CP感染肉鸡耗料增重比的增加(P<0.05);CP感染提高了23日龄肉鸡血清二胺氧化酶(DAO)活力和十二指肠隐窝深度(CD)(P<0.05),并降低了肉鸡十二指肠和回肠绒毛高(VH)、十二指肠绒毛高隐窝深比值(VH/CD)及回肠分泌型免疫球蛋白A(sIgA)含量(P<0.05);添加PE抑制了23日龄CP感染肉鸡十二指肠和回肠VH和VH/CD的降低(P<0.05),并提高了肉鸡血清免疫球蛋白A(IgA)、十二指肠和空肠sIgA含量(P<0.05);CP感染下调了23日龄肉鸡十二指肠Occludin、空肠Claudin-2、回肠Occludin和E-cadherin的相对表达量(P<0.05),但上调了十二指肠Mucin5ac、空肠和回肠Mucin-2、Mucin5ac的相对表达量(P<0.05);PE可增加十二指肠Occludin、Mucin-2、Mucin5ac、E-cadherin、空肠和回肠Mucin5ac的相对表达量(P<0.05),并下调回肠Occludin、Claudin-2、E-cadherin的相对表达量(P<0.05);添加PE提高了CP感染肉鸡十二指肠和空肠Occludin、E-cadherin和回肠Mucin-2、Mucin5ac的相对表达量(P<0.05)。因此,饲粮添加葛根提取物可改善CP感染肉鸡耗料增重比和肠道组织形态,提高肉鸡免疫功能,调控肠道屏障功能相关基因的表达。

The study was conducted to investigate the effect of pueraria extract(PE) on growth performance, intestinal barrier function of broilers challenged with Clostridium perfringens(CP). According to the 2×2 factorial random design, 264 1-dayold female Cobb broiler chicks were randomly assigned into 4 groups: control, CP, PE, and PE+CP groups. Each group had 6 replicates with 11 chickens per replicate. From 1 to 30 days of age, birds in the control and CP groups were fed with basal diets, whereas those in the PE and PE+CP groups were fed with basal diets supplemented with 400 mg/kg PE. From 18 to 23days of age, each broiler in the CP and PE+CP groups was orally administrated with 1×10^(8) CFU type A CP, while chickens in the control and PE groups were treated with sterilized broth medium without CP. The experiment lasted for 30 days. The results showed that dietary supplementation of PE significantly decreased the average daily feed intake(ADFI) in broilers from 1 to 17 days of age(P<0.05). CP infection significantly increased the feed conversion ratio(FCR) in broilers from 18to 23 days of age, while PE inhibited the increase of FCR in broilers challenged with CP(P<0.05). Moreover, CP challenge significantly increased the activity of serum diamine oxidase(DAO) and the duodenal crypt depth(CD) at the age of days 23(P<0.05), but decreased the duodenal and ileal villus height(VH) and ratio of villus height to crypt depth(VH/CD), as well as the levels of ileal secretory IgA(sIgA) at the age of days 23(P<0.05). However, supplementation with PE inhibited the decrease of VH and VH/CD, but elevated the increased the contents of serum IgA, duodeal and jejunal sIgA in broilers in broilers at the age of days 23(P<0.05). QPCR results demonstrated that CP challenge down-regulated the expression of Occludin in the duodenum and ileum, Claudin-2 in the jejunum, and E-cadherin in the ileum(P<0.05), while up-regulated the expression of Mucin5ac in the duodenum, and Mucin-2 and Mucin5ac in the jejunum and ileum of broilers(P<0.05). Dietary supplementation of PE significantly increased the mRNA levels for duodenal Occludin, Mucin-2, Mucin5ac, E-cadherin,jejunal Mucin5ac, and ileal Mucin5ac(P<0.05), but deceased the ileal Occludin, Claudin-2, and E-cadherin mRNA expressions of birds(P<0.05). In addition, dietary supplemented with PE significantly increased the mRNA levels for Occludin, E-cadherin in the duodenum and jejunum, and Mucin-2 and Mucin5ac in the ileum of broilers challenged with Clostridium perfringens.In conclusion, dietary supplementation of PE improved the FCR and intestinal morphology, enhanced the intestinal immunity,and modulated the intestinal barrier function-related gene expression in broilers challenged with CP.