The Effect Of Dietary Lentinan Supplementation On The Growth Performance,Immune Function And Gut Health In Weaned Piglets Challenged By Rotavirus

Rotavirus(RV)challenge model of weaned piglets was built in this experiment,which was conducted to investigate the This experiment was conducted to investigate the effect of dietary lentinan(LNT)supplementation on the growth performance,immune function and intestinal health in the weaned pigs challenged by rotavirus(RV).A total of28 healthy crossbred(Duroc × Landrace × Yorkshire)piglets(7.51 ± 1.37 kg)weaned at 21 d were randomly assigned to one of four groups(n = 7/group)in a 2 × 2 factorial design experiment.Piglets were fed with the two diets supplementing LNT levels of 0 and 84mg/kg(namely two groups per dietary treatment)for 19 d.On d 15,all piglets were orally infused with RV or sterilized MEM medium.The results were listed as follows.(1)On 1?14 d,dietary LNT supplementation reduced F/G in the piglets(P < 0.05).On 15?19 d,RV challenge reduced average daily gain(ADG)(P = 0.08),and raised the diarrhea rate,average diarrhea index,feed/gain(F/G),serum UN level,NSP4 levels of the the jejunal and ileal mucosa,and RV-Ab concentration of the serum,jejunal and ileal mucosa in the piglets(P < 0.05).Dietary LNT supplementation improved ADG(P < 0.05),reduced the F/G and SUN level(P < 0.05),increased nutrient digestibility and RV-Ab levels of the jejunal mucosa in the piglets(P < 0.05);and alleviated the effect of PRV challenge on ADG,F/G,SUN,diarrhea,and serum RV-Ab levels(P < 0.05),and reduced NSP4 levels of the the jejunal and ileal mucosa in the piglets.(2)RV challenge raised serum Ig M,Ig G,Ig A and DAO levels,and reduced s Ig A,IFN-? and IL-4 concentrations of the jejunal and ileal mucosa(P < 0.05),and enhanced IL-2 of the jejunal and ileal mucosa in the piglets(P < 0.05).Supporting LNT in diets enhanced serum Ig M,Ig G(P = 0.08)and Ig A levels,and s Ig A and IFN-? concentrations of the the jejunal and ileal mucosa(P < 0.05),reduced IL-2 concentrations of the jejunal and ileal mucosa,and DAO activities in serum(P < 0.05);and further improved Ig M level in serum of RV-infected piglets,and relieved the effect of PRV challenge on s Ig A,IL-4,IL-2 and IFN--? levels of the jejunal and ileal mucosa as well as serum DAO activities in the piglets(P < 0.05).(3)RV challenge reduced villus height and the villous height to crypt depth ratio(V/C,P < 0.05),and increased crypt depth in the jejunum(P < 0.05).Dietary LNT supplementation raised villus height and V/C(P < 0.05);and attenuated the effect of PRV challenge on intestinal morphology of the jejunum in weaned pigs(P < 0.05).(4)RV challenge decreased the expressions of ZO-1,occludin,Bcl-2,MUC1,MUC2,p BD1,p BD2,p BD3 and PG1-5 in the jejunal and ileal mucosa(P < 0.05),increased the expressions of Bax and/or caspase-3 in the jejunal and ileal mucosa(P < 0.05).Dietary LNT supplementation improved ZO-1,Bcl-2,p BD1,p BD3 and PG1-5 m RNA levels in the jejunal and ileal mucosa(P < 0.05),increased p BD2 and MUC1 m RNA level in the ileal mucosa,and MUC2 m RNA level in the jejunal mucosa(P < 0.05);and relieved the effect of PRV challenge on the expressions of ZO-1,occludin,MUC1,MUC2,p BD1,p BD2,p BD3 and PG1-5 of the jejunal and ileal mucosa in weaned pigs(P < 0.05).(5)RV challenge decreased the number of lactobacillus,bifidobacterium and total bacteria in ileal and cecal digesta(P < 0.05),and increased E.coli in cecal digesta(P <0.05).Dietary LNT supplementation relieved the effect of PRV challenge on the number of lactobacillus,bifidobacterium and total bacteria of the cecal digesta in the piglets(P <0.05).(6)RV challenge reduced the content of acetic acid,propionic acid and total volatile fatty acids(VFA)in cecum of piglets(P < 0.05).Dietary LNT supplementation improved the content of propionic acid and VFA in cecum of PRV-challenge piglets(P < 0.05).(7)RV challenge increased MDA concentrations(P < 0.05),and decreased T-AOC concentrations in the serum,jejunal and ileal mucosa(P < 0.05).Dietary LNT supplementation decreased MDA concentrations in the serum(P = 0.06)jejunal(P < 0.05)and ileal mucosa(P < 0.05),and increased T-AOC concentrations in the serum,jejunal and ileal mucosa(P < 0.05);and alleviated the effect of PRV challenge on T-AOC and MDA concentrations of the serum,jejunal and ileal mucosa in weaned pigs(P < 0.05).In conclusion,these results suggest that RV challenge could decrease antioxidant capacity,intestine damage,immune dysfunction,increasing diarrhea rate and lowering nutrients utilization,which led to the decline of growth performance.However,dietaryLNT supplementation alleviated the growth performance and diarrhea induced by PRV challenge in piglets,which could be due that dietary LNT supplementation might improve the utilization of nutrients,immunity,antioxidant capacity and intestinal barrier function in the weaned pigs.