The Effects Of Diets Fermented With Bacteria And Enzymes On Growth Performance And Intestinal Health In Weaned Piglets

During the weaning period in piglets,a series of problems(retarded growth,high diarrhea rate,etc.)exist widely.Although antibiotics could effectively solve these problems,there are hidden threats to environment and problems of high residual rate.Diets fermented with bacteria and enzymes have the potential value of improving the nutrient digestibility of piglets and balancing the intestinal microflora.Therefore,three experiments(including an in vitro fermentation experiment and two animal experiments)were conducted to study the effects of fermentation of diets with bacteria and enzymes on the quality of diet and the beneficial effect of fermented diet on the growth performance and intestinal health of weaned piglets,which could provide reference for healthy breeding of piglets.Experiment 1 Screening of fermentation process parametersThis experiment was aimed to study the effects of fermentation time,feed water ratio and the addition of enzyme preparation on the quality of fermented feed in the laboratory,and screened the optimal fermentation process parameters.The fermented feed consisted of 36.01% expanded corn,35.69% corn,11.89% soybean meal,11.89% expanded soybean,2.38% sucrose and 2.14% soybean oil.The inoculum of the compound bacteria in the feed was 3 mL/kg,and the compound enzyme preparation was added in an amount of 0%,0.2%,and the ratio of feed to water were 1:0.5,1:1 and 1:1.5,fermentation time was set to 6 h,12 h,18 h,and 24 h.The results showed that the addition of enzyme preparation could greatly increase the content of lactic acid and acid-soluble protein in the feed.The pH of the fermented feed decreased with the increase of water addition.The content of lactic acid increased with the increase of water addition.Prolonged fermentation time significantly increased the content of lactic acid(P<0.05),acid soluble protein and the amount of lactic acid bacteria,which significantly decreased the number of E.coli and the pH of the feed(P<0.05).The experiment showed that fermented with bacteria and enzymes could improve the levels of lactic acid and acid-soluble protein as well as the number of lactic acid bacteria,reduce the pH and the amount of E.coli,and improve the feed quality.According to various process parameters,0.2% enzyme preparation,feed-water ratio 1:0.5,12 h fermentation time were optimum process parameters for the fermentation.Experiment 2 Effects of Diet Fermented for 12 and 24 h on the Growth Performance and Intestinal Health of PigletsA total of 96 piglets(42-d-old,Duroc × Landrace × Yorkshire)with body weight of 8.98±0.75 kg were randomly allocated to 4 treatments with 8 replications per treatment and 3 piglets per pen.They were assigned to the control group(CON),antibiotic group(AB),12 h group(12 h FER)and 24 h fermentation group(24 h FER).The other fermentation conditions were the same with experiment 1.The trial period was 21 days.The results showed that:(1)Compared with CON group,both 12 and 24 h fermented diets significantly increased the ADG of 1-21 d(P<0.05),and the ADG of 24 h FER group was higher than that of AB group(P<0.05).The two fermentation groups(12 h FER group and 24 h FER group)both significantly reduced the F/G and diarrhea rate(P<0.05),and there was no difference among 12 h FER group,24 h FER group and AB group(P>0.05);(2)The digestibilities of DM,CP,EE,Ash,GE,TP in 12 h and 24 h FER groups were higher than those of CON and AB groups(P<0.05),and there was no difference between 12 h group and 24 h FER group;(3)Compared with CON group,the levels of serum IL-6 in 12 h FER group,24 h FER and AB groups were significantly decreased(P<0.05),and there was no difference among these three treatments.The serum MDA level in 12 and 24 h FER groups significantly decreased compared with CON and AB groups(P<0.05);(4)Compared with CON group,the activity of sucrase in jejunum of 24 h FER group significantly increased(P<0.05);(5)Compared with CON and AB groups,the crypt depth of duodenum significantly decreased in 12 h FER group(P<0.05),the duodenal V/C,the number of jejunal GC and ileac villi height significantly increased in 12 h FER group(P<0.05).The duodenal V/C and ileac villi height in 24 h FER group significantly increased compared with CON and AB groups(P<0.05);(6)Compared with CON and AB groups,the mRNA expressions of OCLN and ZO-1 in jejunum as well as CLDN-1 and IGF-1 in ileum significantly increased in 24 h FER group(P<0.05),and OCLN mRNA expression in ileum significantly increased in 12 h FER group(P<0.05);(7)Compared with CON and AB groups,the level of sIgA and the mRNA expression of TGF-? in colon significantly increased in 24 h FER group(P<0.05);(8)The number of Lactobacillus in colon of 12 and 24 h FER groups significantly increased compared with CON and AB groups(P<0.05),the number of E.coli significantly decreased compared with CON group(P<0.05).This experiment showed that fermented diets could improve intestinal health,improve nutrient digestibility,reduce diarrhea rate,thereby improving the growth performance of piglets;the effect of the fermented diets was equivalent to or better than chlortetracycline;12 h fermented diet was almost equivalent to 24 h fermented diet.Experiment 3 Effect of Diet Fermented for 12 h on Growth Performance and Intestinal Health of Weaned PigletsA total of 72 weaned piglets(21-d-old,Duroc × Landrace × Yorkshire)with body weight of 7.21±0.32 kg were randomly allocated to 3 treatments with 8 replications per treatment and 3 piglets per pen.They were assigned to the control group(CON),antibiotic group(AB)and 12 h fermentation group(12 h FER).The experiment period was 49 days.The results showed that:(1)Compared with CON group,12 h FER group significantly increased ADG in 1-42 d(P<0.05),and significantly decreased the diarrhea rate and F/G in 1-42 d(P<0.05),and there was no difference between 12 h FER group and AB group(P>0.05);(2)In 12 h FER group,the apparent digestibilities of DM,CP,EE,Ash,GE significantly increased compared with CON and AB groups(P<0.05);(3)In 12 h FER group,serum MDA and UREA levels were lower than those of CON and AB groups(P<0.05),the ALB in serum was higher than that of CON and AB groups,and the TNF-?,IL-6 as well as DAO levels in serum significantly decreased compared with CON group(P<0.05);(4)The activities of sucrase and amylase as well as lactic acid in the jejunum of 12 h FER group significantly increased compared with CON and AB groups(P<0.05);(5)Compared with CON group,the duodenal V/C and villi height as well as the jejunal V/C significantly increased in 12 h FER and AB groups(P<0.05),and there was no difference between 12 h FER group and AB group.Compared with CON group,the numbers of GC in jejunum and ileum in 12 h FER group significantly increased(P<0.05);(6)Compared with CON and AB groups,the mRNA expressions of CLDN-1 and ZO-2 gene in jejunum,as well as ZO-2 in ileum significantly increased in 12 h FER group(P<0.05);(7)Compared with CON and AB groups,in 12 h FER group,the levels of sIgA in jejunum increased significantly(P<0.05),the expressions of IL-10 and TGF-? genes in jejunum increased significantly(P<0.05),and the mRNA expressions of IL-1? gene in ileum decreased significantly(P<0.05);(8)Compared with CON group,in 12 h FER group,the number of Lactobacillus in colon significantly increased(P<0.05),and the amount of E.coli decreased(P<0.05).The experiment further proved that 12 h fermented diet could significantly improve the intestinal health of weaned piglets,increase nutrient digestibility and growth performance,and the effects were better than those of chlortetracycline.In summary,the results of this study showed that fermentation with compound bacteria and compound enzyme could improve the quality of diets,and the effect was related to the ratio of feed to water and fermentation time.Fermentation at the feed-water ratio1:0.5 for 12 h could significantly improve intestinal health of piglets,increase nutrient digestibility,improve body metabolism and immune function,thereby improving the growth performance,and effects were better than those of dietary supplementation with 75 mg/kg chlortetracycline.