Evaluation Of Efficiency And Tolerance Of Tannalbin And Its Effect On Intestinal Health In Weaned Piglets

Tannalbin is a compound formed by the combination of tannic acid and protein.Its bioactive component tannic acid has potential effects of improving intestinal health and relieving diarrhea of animals.The purpose of this study was to explore the efficiency and tolerance of a new tannalbin product in weaned piglets,to preliminarily explore its possible mechanism to relieve post-weaning diarrhea in piglets,and to provide scientific basis for its utilization in livestock production.In expeiment 1,evaluation of the efficiency of tannalbin in weaned piglets and its effect on intestinal health.A total of 180 Duroc×Landrace×Yorkshire(DLY)piglets of 28 ±1 d with an average initial weight of 7.77 ± 0.17 kg were selected to evaluate the efficiency of tannalbin in weaned piglets and its effect on intestinal health of piglets.The piglets were allotted to 5 treatments(6 pigs/pen and 6 replicates/treatment)in a randomized complete block design according to their gender(half males and half females)and body weight.Dietary treatments were obtained by supplementing the basic diet with 0(control,CON),0.1%,0.2%,0.4% and 0.8% tannalbin.This feeding trial lasted for 28 days.The results showed that,compared with CON group,the addition of tannalbin had no significant effect on growth performance of weaned piglets(P > 0.05),and adding 0.2%～0.8% tannalbin significantly reduced the diarrhea rate and diarrhea index(P < 0.05);Adding 0.8%tannalbin significantly increased the digestibility of ether extract,but decreased the digestibility of crude protein and gross energy(P < 0.05);The addition of tannalbin significantly increased duodenal(0.8%)and jejunal(0.1%,0.4% and 0.8%)villus height(P < 0.05);Adding 0.4% tannalbin significantly improved the activity of catalase in serum(P < 0.05);Adding 0.8% tannalbin significantly reduced the p H value of cecal and colonic contents(P < 0.05);The addition of tannalbin significantly up-regulated jejunal zonula occludens-1(ZO-1)(0.8%),zonula occludens-2(ZO-2)(0.1%,0.4% and 0.8%)and claudin-2(CLDN-2)(0.4%)m RNA expression levels(P < 0.05),increased the number of Bacillus in cecal(0.1%～0.8%)and colonic(0.8%)contents,reduced the number of Escherichia coli in colonic(0.2%)contents(P < 0.05),increased the concentration of acetic acid(0.4%),propionic acid(0.4% and 0.8%),butyric acid(0.1%～0.8%)and isovaleric acid(0.2%～0.8%)in cecal contents and acetic acid(0.8%)in colonic contents(P< 0.05).In conlusion,adding tannalbin to diets did not affect growth performance of piglets,but it can reduce the diarrhea rate and diarrhea index of piglets,improve intestinal morphology,improve the body’s antioxidant capacity,up-regulate the expression of intestinal tight junction protein-related genes,improve the balance of the hindgut flora and increase the content of volatile fatty acids,and the suitable dosage is 0.2%～0.4%.In expeiment 2,evaluation of the tolerance of tannalbin in weaned piglets and its effect on intestinal barrier.A total of 144 DLY(26 ± 1 d)piglets with an average initial weight of 6.60 ± 0.27 kg were selected to evaluate the tolerance of tannalbin in weaned piglets and its effect on intestinal barrier.The piglets were allotted to 4 treatments(6pigs/pen and 6 replicates/treatment)in a randomized complete block design according to their gender and body weight.Dietary treatments were obtained by supplementing the basic diet with 0(control,CON),0.4%,2.0% and 4.0% tannalbin.And the CON group,0.4%and 2.0% tannalbin groups were selected to explore the effect of tannalbin on intestinal barrier integrity and function of weaned piglets.This feeding trial lasted for 28 days.The results showed that,compared with CON group,the addition of 0.4%,2.0% and 4.0%tannalbin had no significant effect on growth performance of weaned piglets(P > 0.05),and adding 0.4% or more tannalbin reduced the diarrhea rate and diarrhea index of weaned piglets(P < 0.05 or 0.10);Adding 2.0% and 4.0% tannlbin increased the number of red blood cells in blood,reduced the liver index(P < 0.05),and caused the expansion of germinal center of local lymph nodules in mesenteric lymph nodes;Adding 0.4% and 2.0%tannalbin reduced the diamine oxidase activity and D-lactate concentration in serum(P <0.05);Adding 0.4% tannalbin reduced the crypt depth and increased the villus height to crypt depth ratio of duodenum(P < 0.05),but adding 2.0% tannalbin reduced the villus height of ileum(P < 0.05);Addition of 2.0% tannalbin reduced the content of malondialdehyde in ileum mucosa(P < 0.05);Addition of tannalbin increased duodenal ZO-2(0.4%)and occludin(OCLN)(0.4% and 2.0%)m RNA expression levels(P < 0.05),and increased the localization and expression of duodenal(0.4% and 2.0%),jejunal(2.0%)and ileal(2.0%)occludin(P < 0.05).In conclusion,the addition of tannalbin in the diet can effectively improve intestinal barrier integrity and function of piglet.Although the addition of 2.0% and 4.0% tannalbin reduced the liver index of piglets,it had no negative impact on growth performance and histopathology.And the hematology index had been improved to some extent,indicating that 4.0% tannalbin is relatively safe for weaned piglets.To summary,under the conditions of this experiment,the addition of tannalbin to piglet diets can promote intestinal health by improving intestinal barrier integrity and function,and alleviate post-weaning diarrhea of piglets.The suitable dosage of tannalbin is0.2%～0.4% and the tolerance dose up to 4.0%.