Study On The Feeding Effect Of Fermented Chinese Herbal Residues In Weaned Piglets

Chinese herbal residues(CHR)are produced during Chinese herbal production and processing,which contains a lot of nutrients and active ingredients.However,utilization of CHR has been very little,which causes serious waste of resources and environmental pollution.After the process of microbial fermentation,anti-nutritional factors are reduced,a large number of functional secondary metabolites are produced and the function is enhanced.To evaluate the possibility of fermented CHR as feed additive,180 piglets weaned at 21 days of age were randomly assigned to 6 treatment groups,representing blank control group,CHR 1 group(supplementing dose 4 kg/t),fermented CHR 1 group(supplementing dose 4 kg/t),CHR 2 group(supplementing dose 5 kg/t),fermented CHR 2 group(supplementing dose 5 kg/t),and positive control group(supplementing 0.04 kg/t virginiamycin,0.2 kg/t colistin and 3000 mg/kg zinc oxide).There were 5 replicates per treatment group and 6 animals per replicate.Daily feed intake of per column was recorded everyday;at day 1,7 and 28 d of the experiment,the weight of all piglets were weighed on an empty stomach;the data of growth performance was calculated at last.At day 7 and 28 d,the fresh fecal samples were collected in the morning in each column of piglets and stored at-20 ? for the determination of digestibility,and blood samples were collected for determination of biochemical parameters and the antioxidant index.After a 28-day feeding period,a medium-sized piglet of per replicate was slaughtered to collect samples of the jejunum,ileum,colon to observe the morphology of jejunum and analyse mRNA levels of colonic tissue,while collect ileum colonic contents to analyse the quantity of colonic microorganisms,concentrations of microbiotic metabolites.Data showed that:(1)The F/G in fermented CHR 1 group was lower compared with the blank control and CHR groups in each experiment stage,diarrhea rate was significantly higher compared with positive control group,the digestibility is higher than other three groups.At day 7 of the experiment,the plasma total protein content of the fermented CHR 1 group was significantly higher compared with the positive control group(P<0.05),the plasma alanine aminotransferase(ALT)activity was significantly lower compared with the blank control group(P<0.05).At day 28 of the experiment,the plasma activities of catalase,glutathione peroxidase,and the contents of glutathione of the fermented CHR 1 group were higher,while the contents of malondialdehyde was lower compared with the positive control group(P>0.05);the jejunum V/C was minimum,and villi width was maximum.the concentrations of indole in the colonic content decreased when compared with positive control group(P<0.05),increased the messenger RNA levels of interleukin 1 alpha,interleukin 2 and tumour necrosis factor alpha,as well as decreased interleukin 12 in comparison to blank control group(P<0.05).In addition,dietary supplementation with CHR increased(P<0.05)the messenger RNA of E-cadherin in comparison to other three groups,as well as zonula occludens 1 in comparison to blank control group(P<0.05),and the quantities of Bifidobacterium spp in CHR group were markedly lower as compared with blank control group(P<0.05).(2)The F/G in fermented CHR 2 group was lower(P>0.05)compared with the blank control group and CHR 1 group in the whole experiment stage;diarrhea rate was significantly higher compared with positive control group;at day 7 of the experiment,the digestibility of DM,GE,EE,and CP were higher(P>0.05)than those in blank control group and positive control group,while lower at day 28 of the experiment.At day 7 of the experiment,the plasma TP and GLB contents and ALB/GLB ratio significantly increased(P<0.05)when compared with the two control groups,as well as TG content compared with the positive control group,while significantly decreased(P<0.05)the plasma AST activity compared with the blank control group,as well as the ALP activity compared with the CHR group and two control groups;at day 28 of the experiment,HDL-C content and SOD activity in fermented CHR 2 group decreased compared with the CHR 2 group,and GSH-PX activity compared with the CHR 2 group and positive control group.The villus height and V/C of jejunum and ileum were higher,and the crypt depth and villus width were lower than that in the CHR 2 group.the colonic contents of acetate,butyrate,valerate,isobutyrate,SCFAs and total short-chain fat acids,as well as the expression level of IL-4 mRNA significantly decreased(P<0.05),when compared with the CHR 2 group.The plasma TP and TC content significantly increased(P<0.05)in CHR 2 group,while decreased ALB/GLB ratio(P<0.05)compared with the positive control group.Dietary supplementation with CHR 2 or fermented CHR 2 did not affact(P>0.05)the amounts of seven tested bacteria and total bacteria compared with the blank control group,while significantly decreased(P<0.05)the expression levels of IL-12 mRNA compared with the two control groups,and indole content compared with the positive control group.The expression level of GM-CSF mRNA significantly increased(P<0.05),while the amounts of Bacteroidetes and Clostridium cluster XIVa decreased(P<0.05)in the positive control group when compared with the blank control group.These findings suggested that the fermented CHR 1 can improve the growth performance,digestibility and the antioxidant capacity of weaned piglets in a certain extent,present a certain roles in protecting liver and regulating plasma lipid concentration of weaned piglets.The CHR 2 can improve immunity in weaned piglets,increase the contents of SCFAs in colonic content and regulate the colon expression of cytokines in weaned piglets.The fermented CHR 2 could improve the intestinal morphology of weaned piglets in a certain extent;antibiotics and zinc oxide,not CHR 2 or fermented CHR,affect the balance of intestinal microflora;the microbe fermentation doesn't enhance the improvement of CHR on intestinal microbe metabolism.