Effects Of Gallnut Tannin Acid On The Growth Effect Of Weaned Piglets

Due to the prohibition of antibiotics and high frequency of diarrhea in weaned piglets,therefore,it is urgent to explore antibiotic alternatives to prevent and control diarrhea of piglets.The objective of the present study was to determine growth performance,nutrients digestibilities,digestive enzyme activities,small intestinal structure and function,antioxidation and anti-inflamattary to reveal the response and regulation pathway of tannic acid in diarrhea of piglets,and furtherly expected to provide theoretical basis for its application in pig production.One hundred and fifty(Duroc×Landrace×Yorkshire)24-day-old weaned piglets with body weight of 7.07 ± 0.06 kg were randomly divided into 5 groups with 5replicates in each treatment and 6 weaned piglets per replicate.Piglets in the control group were fed with basic diet,and piglets in AMP,GTA700,GTA1 200 and GTA1 700 were fed with diets antibiotics,700,1200 and 1700 mg/kg GTA inclusion,respectively.There were 4d for pre-trial and 28 d for trial.Body weight,feed intake,stool scores were recorded.And ADG,ADFI,F/G,diarrhea frequency and diarrhea index were calculated.At 28 th day,one piglet per replicate was randomly selected and infused 10%D-xylose,then blood samples were collected after 1 hour.Serum and plasma were prepared and blood biochemical indexes were analyzed.Piglets were slaughtered,organs were weighed and the organ index was calculated.The small intestinal chyme was sampled and the activities of digestive enzymes were determined.2 cm segment of duodenum,jejunum and ileum were sampled,and fixed with 10% neutral formaldehyde,and slices were made to observe intestinal morphology.Another 5 cm of intestinal mucosa was scraped and mucosal development was measured.The caecal contents were collected and the flora structure was determined.Content 1: Effects of GTA on growth performance and nutrients digestion in weaned piglets.The results showed that: 1)Antibiotics and GTA had a tendency to promote feeding intake(P=0.055),and promoted the growth of piglets.In addition,ADG increased with the GTA level(P<0.05),and GTA1 700 group ADG is close to antibiotic group,but the feed utilization efficiency F/G has no significant influence(P>0.05).2)Trypsin activities in duodenal were increased by GTA(P<0.05),but the antibiotic group had no significant influence on trypsin activity(P<0.05).Suggested that GTA increased digestive enzyme activity,but antibiotics did not affect digestive enzyme activity.In addition,there were no significant influence on the activities of duodenal α-AMS and LPS(P>0.05),trypsin,α-AMS and LPS activities in jejunum and ileum(P>0.05).3)Apparent digestibilities of calcium from GTA group were higher than control and antibiotic(P=0.07),especially in the GTA 1 200 group,but there were no significant difference in apparent digestibilityies of DM,GE,CP,EE,and P among groups(P>0.05).Content 2: Influence of GTA on diarrhea and intestinal function in weaned piglets.The results revealed: 1)Diarrhea rate(P<0.001),diarrhea index(P<0.001),and fecal moisture(P<0.001)were reduced by GTA,significantly,particularly,the GTA1700 group was decreased of diarrhea rate,diarrhea index,and fecal moisture.Therefore GTA alleviated diarrhea of piglets.2)GTA significantly increased villus height of jejunum and ileum(P<0.01),decreased crypt depth of duodenum(P<0.01),and improved ratio of jejunum and ileum to crypt(P<0.05).Therefore the intestinal morphology was ameliorated by GTA.3)GTA promoted the secretion of GLP-2(P=0.049),and the GTA1 200 group was higher antibiotics group significantly.In addition,GTA improved the DNA concentration in duodenum and jejunum(P<0.05),and tended to increase the activity of i-NOS in ileum(P=0.07),and promoted the development of the small intestine.4)GTA had no significant effect on intestinal absorption(P>0.05)and intestinal permeability(P>0.05).5)There was no significant difference in the number of intestinal bacteria(OTU)among groups(P>0.05).Alpha diversity analysis showed that Shannon index and Simpson were affected by GTA inclusion(P<0.05).However,there was no significant difference of microbial abundance(SOBS,ACE,CHAO1)among groups(P>0.05).P-Co A analysis showed that GTA and antibiotics had significant effects on intestinal flora of piglets(P<0.05),but there was no significant difference between antibiotics and GTA groups(P>0.05).The difference analysis of flora structure showed that profile of Firmicutes and Actinomyces enhanced by GTA(P<0.05)and profile Bacteroidetes and RC9 were significantly decreased(P<0.05)at the phylum level.In short,GTA promoted the proliferation of beneficial bacteria,and the effect of adding 1 700 mg/kg GTA is best.Content 1: Effects of GTA on antioxidant activity and tissue damage in weaned piglets.The results showed as follows: 1)Control and antibiotic group activity of GSH-Px were no significant difference(P> 0.05),but the serum activity of GTA group were decreased(P<0.01),especially in GTA1200 group.Results indicated that GTA reduces serum antioxidant enzyme activity,but antibiotics did not reduce it.Antibiotics and GTA had no significant effects on liver antioxidant(GSH,GSH-Px,TSOD and MDA),immunity(Ig A and Ig G)and inflammatory response(TNF-α,IL-6,IL-1α and PGE2)(P>0.05).2)Antibiotics and GTA had no significant effects on indexes of heart,liver,spleen,lung,kidney,stomach,small intestine and large intestine of piglets(P>0.05),indicating that GTA did not damage tissues and organs.3)Antibiotics and GTA had no significant effects on blood metabolic indexes Glu,TP,BUN and TG(P>0.05).In conclusion,GTA improves feed intake,increases trypsin activity,and promotes growth of piglets.GTA ameliorates intestinal morphology,promote intestinal development,increased the abundance of beneficial bacteria,and alleviated diarrhea of piglets.GTA had no significant effects on immunity,anti-inflammation and liver antioxidant in piglets,but decreased serum GSH-Px activity.Under the conditions of this experiment,the recommended dosage of GTA is 1 700 mg/kg.