Effects Of Lactobacillus Fermentum And Bacillus Coagulans On The Growth Performance And Gut Health Of Broilers Challenged With Clostridium Perfringens

In the present study,the infectio of broiler chickens was induced with the challenge of Clostridium perfringens.The aim was to investigate the effects of Lactobacillus fermentum and Bacillus coagulans on the growth performance and gut health of infected birds.A total of 336 1-day-old Arbor Acres chicks were randomly assigned into 4 groups with 6replicates per group.The four treatments were the control,birds challenged with C.perfringens,infected birds fed diets supplemented with L.fermentum?1×10⁹ CFU/kg diet?and B.coagulans(1×10¹⁰ CFU/kg diet),respectively.All infected broilers were inoculated with C.perfringens type A during days 14-21.The experiment lasted for 28 days.The results were showed as following:?1?Growth performance:Compared with the control group,the C.perfringens challenge decreased daily weight gain and daily feed intake by 3.11%and 4.17%during days 15-21?P>0.05?,and significantly decreased the daily feed intake during days 22-28?P<0.05?.Compared with the infected group,dietary supplementation with L.fermentum increased the daily weight gain and daily feed intake by 3.21%and 2.00%during days 15-21,and significantly decreased daily gain and daily feed intake during days 22-28?P<0.05?.Dietary supplementation with B.coagulans increased the daily gain and daily feed intake by 2.80%and 3.49%during days 15-21?P>0.05?.?2?Intestinal injury and intestinal morphology:Compared with the control group,the C.perfringens challenge significantly increased the duodenal and jejunal lesion scores and pH at d 28?P<0.05?.Compared with the infected group,dietary supplementation with B.coagulans significantly decreased the duodenal lesion score at d 28 and duodenal crypt depth at d 21?P<0.05?,and increased the jejunal ratio of villus height to crypt depth?P<0.05?.?3?Expression of genes associated with intestinal mucosal barrier function:Compared with the control group,the C.perfringens challenge significantly up-regulated the mRNA levels of duodenal claudin-1,mucin-2,ZO-1,jejunal mucin-2,ZO-1,ileal claudin-1 at d 21and duodenal mucin-2 at d 28?P<0.05?.Compared with the infected group,dietary supplementation of L.fermentum significantly up-regulated the mRNA levels of ZO-1 in duodenum at d 21 and jejunum at d 28?P<0.05?,down-regulated duodenal occludin,mucin-2 and ileal claudin-1 at d 21?P<0.05?.B.coagulans significantly up-regulated the expression of duodenal ZO-1,jejunum claudin-1,occludin at d 21?P<0.05?,and significantly down-regulated duodenal occludin,mucin-2,ileum claudin-1 expression at d21?P<0.05?.Both L.fermentum and B.coagulans significantly down-regulated the mRNA levels of duodenal claudin-1,occludin,ZO-1,jejunal occludin,ileal claudin-1,occludin at d 28?P<0.05?.?4?Expression of genes associated with intestinal immunity:Compared with the control group,the C.perfringens challenge up-regulated the mRNA levels of intestinal IFN-?at d 21 and duodenal iNOS,ileal iNOS and TNF-?at d 28?P<0.1?and significantly up-regulated the expression of duodenal iNOS and ileal plgR at d 21?P<0.05?.Compared with the infected group,dietary supplementation of L.fermentum increased the intestinal IFN-?expression?P<0.1?,significantly up-regulated the jejunal and ileal mRNA levels of TNF-??P<0.05?and down-regulated the duodenal mRNA expression of iNOS?P<0.05?.Dietary supplementation of B.coagulans significantly up-regulated the mRNA level of IFN-?,plgR in duodenum at d 21 and jejunal IFN-?at d 28?P<0.05?,down-regulated the ileal expression of iNOS at d 28?P<0.05?.Compared with the control group,the C.perfringens challenge significantly up-regulated the mRNA levels of jejunal IL-1?,IL-4,IL-8 and ileum IL-1?,IL-8?P<0.05?,up-regulated the mRNA levels of duodenal IL-1?and ileum IL-4,IL-17 at d 21?P<0.1?.Compared with the infected group,dietary supplementation of L.fermentum or B.coagulans significantly down-regulated mRNA levels of jejunal IL-8 and ileal IL-1?,IL-4,IL-8 and B.coagulans significantly decreased jejunal IL-1?and ileal IL-17 expression at d21?P<0.05?.Compared with the control group,the C.perfringens challenge significantly up-regulated the mRNA levels of duodenal AvBD1,AvBD5 and jejunal AvBD14 at d 21?P<0.05?.Compared with the infected group,dietary supplementation of L.fermentum significantly down-regulated the mRNA expression of jejunal AvBD14 at d 21 and AvBD1,AvBD14 at d 28?P<0.05?.Dietary supplementation of B.coagulans significantly down-regulated the mRNA expression of duodenal AvBD5,jejunal AvBD14 at d 21 and jejunal AvBD5,AvBD14 at d 28?P<0.05?.?5?Intestinal pH and microflora:Compared with the control group,the C.perfringens challenge significantly increased the duodenal and jejunal lesion scores and pH at d 28?P<0.05?.Compared with the infected group,dietary supplementation with L.fermentum significantly decreased the pH in the duodenum,jejunum and caecum at d 28?P<0.05?,and Dietary supplementation with B.coagulans significantly decreased the pH in the small intestine and cecum at d 28?P<0.05?.Compared with the control group,the C.perfringens challenge significantly increased the cecal contents of C.perfringens and Escherichia.Coli at d 21?P<0.05?,significantly decreased the contents of C.perfringens in ileal?P<0.05?,increased the contents of C.perfringens in the cecum?P=0.070?,decreased the cecal contents of E.Coli?P=0.080?at d28.Compared with the infected group,dietary supplementation with L.fermentum significantly increased the ileal contents of Lactobacillus spp.?P<0.05?,decreased cecal content of E.coli at d 21?P<0.05?.Dietary supplementation with B.coagulans significantly increased the contents of Lactobacillus spp.in the ileum at d 28?P<0.05?,decreased the contents of E.coli in ileum and cecum at d 21?P<0.05?.Dietary supplementation with L.fermentum or B.coagulans tended to decrease C.perfringens in cecum at d 28?P=0.070?.Conclusion:Although dietary supplementation of 1×10⁹ CFU/kg Lactobacillus fermentum and 1×10¹⁰ CFU/kg Bacillus coagulans did not significantly improve the growth performance of broilers infected with Clostridium perfringens,the intestinal barrier and immune function of broilers infected with Clostridium perfringens were enhanced by regulating the genes mRNA levels of intestinal barrier and immunity,which promoted the proliferation of Lactobacillus spp in hindgut and alleviated intestinal injury.In the experiments,Bacillus coagulans was more effective than Lactobacillus fermentum.