| This study was conducted to investigate the effect of berberine(BBR)on growth performance,and intestinal health of weaned piglets infected with enterotoxigenic Escherichia coli K88.A total of 64 Duroc×Landrace×Yorkshire weaned piglets(castrated boars)were randomly divided into four groups,with 8 replicates of 2 pigs each group.The four treatment groups included:Control group,BBR group,ETEC group and ETEC+BBR group.The piglets in Control group and ETEC group were fed with basal diet,while those in BBR group and ETEC+BBR group were fed with basal diet supplemented with 250mg/kg BBR.The trial period lasted for 18 days.On the 15th and 17th days of the trial period,piglets in ETEC group and ETEC+BBR group were challenged with 10 m L ETEC K88 suspension(1×10~9 CFU/m L),while the control group and BBR group were treated with the same amount of sterilized PBS.The average daily gain(ADG),average daily feed intake(ADFI),ratio of feed to gain(F/G)and the diarrhea rate of piglets were calculated,respectively.At the end of the experiment,one piglet from each pen was randomly selected for slaughter and sample collection to study the effects of BBR on serum biochemical parameters,intestinal morphology,and intestinal gene expression in weaned piglets challenged with enterotoxigenic Escherichia coli K88.The results showed that:1)Compared with the Control group,the ADG and F/G at d1～18 in piglets in ETEC group were significantly decreased(P<0.05).Compared with the Control group,the ADG,ADFI and F/G at d15～18 in piglets in ETEC group were significantly decreased(P<0.001),while diarrhea rate was significantly increased(P<0.05).Pretreatment with BBR significantly increased the ADG,ADFI,and F/G,and decreased diarrhea rate in ETEC infected piglets(P<0.05).2)Compared with the Control group,the serum concentration of total bile acid of piglets in BBR group was significantly decreased(P<0.05),while lactate dehydrogenase content had the tendency to decrease(P=0.08).The serum levels of aspartate amino transferase and total bile acid in piglets of ETEC group were significantly decreased(P<0.05),while serum total bilirubin concentration was significantly increased when compared with the Control group(P<0.05).3)Compared with the Control group,BBR group significantly decreased the crypt depth of ileum,increased the ratio of villus height to crypt depth in the ileum(P<0.05).ETEC group significantly decreased the ratio of villus height to crypt depth(P<0.05).However,the villus height,and villus height to crypt depth of ileum in ETEC+BBR group were significantly increased compared with ETEC group(P<0.05).4)Compared with the Control group,the concentrations of TNF-αand IL-17 in jejunal mucosa and IL-1β,and IL-10 in colonic mucosa of piglets in BBR group were significantly decreased(P<0.05);The concentration of IL-1βin jejunal mucosa of piglets in ETEC group was significantly increased when compared with the Control group(P<0.05);Pre-feeding BBR diet could significantly inhibit the increased concentration of IL-1βin jejunal mucosa of piglets induced by ETEC challenge(P<0.05),and significantly reduced the concentration of TNF-αand IL-17 in colonic mucosa(P<0.05).5)The expression levels of ZO-1,and occludin in colon mucosa as well as p BD2 in ileum mucosa in BBR group were significantly higher than those in the Control group(P<0.05).Compared with ETEC group,pre-feeding BBR diet significantly inhibited the down-regulation of occludin,mucin 2 and p BD2 in ileum mucosa and p BD1 in jejunal mucosa of piglets infected with ETEC(P<0.05).In addition,the serum LPS concentration in ETEC group was significantly higher than that in Control group(P<0.05).6)Compared with the Control group,ETEC significantly reduced the expression of TLR2 in colonic mucosa(P<0.05).Compared with ETEC group,pre-feeding BBR diet significantly inhibited the down-regulation of NOD1 and NOD2 expression in colonic mucosa of piglets infected with ETEC(P<0.05).In conclusion,dietary BBR supplementation may alleviate the decline of growth performance induced by ETEC challenge,decrease the incidence of diarrhea,and attenuate the intestinal morphological damage by decreasing the seretion of inflammatory cytokines,thus maintaining the intestinal health of piglets. |
