Effects Of Anethole On Growth Performance And Intestinal Health Of Weaned Piglets

This study aimed to investigate the effects of dietary anethole supplementation on growth performance,immunological parameters,intestinal barrier function and enteric microorganism of weaned piglets challenged with enterotoxigenic Escherichia coli K88(ETEC).A total of 36 piglets weaned at 24±1d of age(Duroc×Landrace×Yorkshire,castrated males,7.50±1kg)were randomly allotted by body weight to four treatments.The four treatments included the control group(CON),the challenge group(ETEC),the antibiotic group(ANT)and the anethole group(EO).Among them,the CON and ETEC groups were fed a basal diet,the ANT group was fed a basal diet supplemented with antibiotics(50mg/kg of quinocetone+75mg/kg of aureomycin+50mg/kg of kitasamycin),and the EO group was fed a basal diet supplemented with 300mg/kg of anethole,for 19 days.On day 12,ETEC,ANT and EO groups challenged with 10 m L Nutrient Broth with 5×10~9 CFU/m L ETEC(CVCC225,China Veterinary Culture Collection Center),CON group received either 10 m L of sterilized Nutrient Broth.Continue to feed for 7 days,during these days,collected blood samples and recorded piglets’weight(BW),feed intake,rectal temperature,and fecal scores.At the end of the test,all piglets were slaughtered for intestine and feces samples.The results show that:(1)ETEC challenge effect no significant difference on ADFI(P>0.05),but ETEC challenge made 31%reduce of ADG,27.21%increase of F/G,and also caused the diarrhea of piglet and rectal temperature significantly increased(P<0.05),while the ANT and EO groups made 32.2%and 28.3%increase of ADG,and 18.72%and17.11%reduce of F/G compared with ETEC group(P<0.05),and alleviated diarrhea,lower rectal temperature caused by ETEC challenge.(2)Within 24h after ETEC challenge,the concentration of IL-1β,IL-6,and IL-10 in blood of piglets was significantly higher in ETEC group compared with those in CON group(P<0.05),but no significantly higher was found in ANT and EO groups.The concentration of TNF-αwas also higher in ETEC group after ETEC challenge,but no statistical difference was found(P>0.05).Within 48h after ETEC challenge,the concentration of IL-12 in blood of piglets was significantly higher in ANT and EO groups compared with those in CON and ETEC groups(P<0.05),the concentration of IFN-γwas also higher in ANT and EO groups,but no statistical difference was found(P>0.05).(3)The villus height decreased(P<0.05),and crypt depth and villus height to crypt depth ratio increased(P<0.05)in the duodenum and jejunum after ETEC challenge compared with the CON group,but ANT and EO groups decreased these changes,no statistical difference was found in the ileum.(4)ETEC challenge increased the activated level of TLRs/My D88/NF-κB signaling pathway(P<0.05),and resulted in the expression of IL-1β,TNF-α,IL-6,and IL-10 genes(P<0.05),but antibiotics or anethole diet supplement could significantly activate the negative feedback regulation mechanism on the TLRs/My D88/NF-κB signaling pathway(P<0.05),decreased the activated level of TLRs/My D88/NF-κB signaling pathway.(5)ETEC challenge could significantly inhibit the expression of Mucin-1,Mucin-2,and p BD-2 genes in the jejunum and ileum(P<0.05),and antibiotics or anethole diet supplement could significantly alleviate this inhibition.(6)The expression of ZO-1,Occludin,and Claudin-1 genes was significantly reduced in ETEC group(P<0.05),and the same of protein abundance(P<0.05),but antibiotics or anethole diet supplement in ANT and EO group was not significantly reduced found.(7)ETEC challenge significantly changed the structure of the intestinal flora of piglets(P<0.05)and damaged the homeostasis of intestinal microorganisms.Antibiotics diet supplement could change the intestinal flora structure of piglets,the effects of anethole diet supplement on intestinal flora of piglets were similar to antibiotics.In summary,dietary anethole supplementation can improve the growth performance and reduce diarrhea of weaned piglets caused by ETEC infection,improve the immune function and intestinal barrier function of piglets,and improve the intestinal flora structure.