Effects Of Compound Chinese Herbal Medicine Preparations On Growth Performance,antioxidation,immunity And Intestinal Health Of Weaned Piglets Under Different Sanitary Environments

In this experiment,the immune challenge model of piglets was constructed with different sanitary environments,and the effects of compound Chinese herbal medicine preparations on growth performance,antioxidation,immunity and intestinal health of weaned piglets in different sanitary environments were explored.The 2×2 factorial arrangement was adopted,the factors were 2 sanitary environments(i.e.,clean and dirty)and2 dietary treatments(control group and additive group).The piglets in control group were fed a corn-soybean meal basal diet,and piglets in additive group were fed an experimental diet which supplemented with compound Chinese herbal medicine preparation based on the basal diet.The trade name of this preparation was "Shanhuasu",which was composed of astragalus polysaccharide,fructus corni and cortex phellodendri extract,the content of astragalus polysaccharide was 240 mg/g.The experiment used 72 duroc×landrace×yorkshire piglets weaned at 28 days of age and assigned to 4 groups according to initial body weight(7.82 ±0.55 kg).Each group contained 6 replicates and each replicate contained 3 piglets.The trail period was 35 days,which was divided into two phases: early period(1 to14 d)and later period(15 to 35 d),the amount of "Shanhuasu" added to the diet was respectively 0.1%and 0.05%.Piglets were slaughtered on day 14 and the venous blood of the piglets was collected on day 14 and 35.The results showed as follows:1)Under the dirty environment,the ammonia concentration in the barn was significantly increased(P<0.05).During the early and later period of the experiment,the severe diarrhea rate and diarrhea index were greater in piglets housed in dirty environment than in piglets housed in clean environment(P<0.05),and there was no significant difference in diarrhea rate and diarrhea index between the 2 diets(P>0.05).There was no significant difference in the average daily gain(ADG)and average daily feed intake(ADFI)between the 2 sanitary environments(P>0.05),and the ratio of feed to gain(F/G)had a tendency to be increased for piglets housed in dirty environment only during the later period(P=0.070).Piglets fed the diet supplemented with compound Chinese herbal medicine preparation had increased ADG and ADFI than those fed the control diet during the early period(P<0.05),there was no significant difference in ADG and ADFI between the 2 diets during the later period(P>0.05).Piglets fed the diet supplemented with compound Chinese herbal medicine preparation had reduced F/G(P=0.068)during the early period and greater body weight at 14 and 35 d postweaning(P<0.05).2)Piglets housed in dirty environment had less activity of serum superoxide dismutase(SOD)(P<0.05)and greater content of liver malondialdehyde(MDA)(P=0.079)compared with those housed in clean environment on day 14.Piglets housed in dirty environment and fed the diet supplemented with compound Chinese herbal medicine preparation had increased activity of serum SOD on day 14 and total antioxidant capacity(T-AOC)on day35 than those fed the control diet(P<0.05),whereas there was no significant difference for piglets housed in clean environment(P>0.05).Piglets housed in clean environment and fed the diet supplemented with compound Chinese herbal medicine preparation had greater activity of liver glutathione peroxidase(GSH-Px)than those fed the control diet(P<0.05),whereas there was no significant difference for piglets housed in dirty environment(P>0.05).3)On the 35 th day of the experiment,piglets housed in dirty environment had greater concentration of serum IL-1β than those housed in clean environment(P<0.05).Piglets fed the diet supplemented with compound Chinese herbal medicine preparation had depressed serum IL-1β concentration than those fed the control diet on day 35(P<0.05)and inhibited ileal TLR4 / NF-κB signaling pathway,they displayed depressed the gene expression level of TLR4,NF-κB,IL-6 and TNF-α(P<0.05),and there was a tendency to decrease the gene expression level of IL-1β(P=0.068)regardless of sanitary environments.Piglets housed in dirty environment and fed the diet supplemented with compound Chinese herbal medicine preparation had decreased the gene expression level of ileal My D88 and IL-10 than those fed the control diet(P<0.05),whereas there was no significant difference for piglets housed in clean environment(P>0.05).However,under different sanitary environments,piglets fed the diet supplemented with compound Chinese herbal medicine preparation had reduced the gene expression level of colonic and ileal ZO-1(P<0.05),ileal Occludin(P=0.053),but differently increased the gene expression level of ileal MUC-2(P<0.05).4)16S r RNA sequencing analysis showed that the microbial community structure(αand β diversity)of colonic chyme in piglets was significantly different between the 2 sanitary environments(P < 0.05).Piglets housed in dirty environment had increased relative abundance of harmful bacteria(Actinobacteria,Clostridiales,Turicibacter and Romboutsia)related to the occurrence of enteritis compared with those housed in clean environment(P< 0.05),while the relative abundance of beneficial bacteria Blautia(P = 0.058)and Roseburia(P=0.073)both tended to decrease for piglets housed in dirty environment.Under different sanitary environments,Piglets fed the diet supplemented with compound Chinese herbal medicine preparation had greater shannon index(P= 0.053)in alpha diversity of intestinal flora and the relative abundance of beneficial bacteria Butyricicoccus(P<0.05)than those fed the control diet.The abundance of KEGG pathway related to host immunity had a tendency to be increased(P<0.10)or was significantly increased(P<0.05),the gene expression level of colonic IL-1β(P=0.080)had a tendency to be increased,and Occludin(P<0.05)was significantly decreased for piglets housed in dirty environment.5)On the 35 th day of the experiment,piglets housed in dirty environment had greater concentration of serum urea,total protein and IgM than those housed in clean environment(P<0.05).Piglets housed in dirty environment had increased the relative length of intestine and small intestine compared with those housed in clean environment(P<0.05),and there was no significant difference in the relative length of large intestine between the 2 sanitary environments(P>0.05).In conclusion,under the dirty environment,the ammonia concentration in the barn increase,the diarrhea rate and diarrhea index of piglets increase,and piglets develop oxidative stress and a moderate inflammatory response.The addition of compound Chinese herbal medicine preparation called "Sanhuasu" in the diet can partially improve the redox status and immune function of weaned piglets,and promote intestinal health,thereby improving growth performance,and this effect is more obvious in the dirty environment.