Effects Of Compound Additives On Growth Performance And Gut Health In Piglets Challenged With Feed Contaminated With Mycotoxins

It has been wordwide concerned that feedstuff and formulated feed are contaminated by mycotoxins.Intestinal cells are the first line of defence to be exposed to mycotoxins,and ofen at higher concentrations than other tissues.This experiment was conducted to study the protective effects of several compound additives on growth performance and gut health and the possible pathway in piglets challenged with feed contaminated with mycotoxins.Experiment 1 Nutritional Compound Additive Alleviates Jejunal Mucosal Structure and Function Disruption in Piglets Challenged with Feed Containing Maize Naturally Contaminated with MycotoxinsThis experiment was conducted to study the protective effects of nutritional compound additive on jejunal mucosal structure and function,redox status and the number of bacterias in caecum and colon content in piglet challenged-with feed contained maizenaturally contaminated with mycotoxins.Eighteen DLY piglets were randomly allocated to control group,naturally contaminated maize group and naturally contaminated maize+0.2%nutritional compound additive group with 6 replicates per treatment and 1 piglet per replicate.The trial lasted for 30 d.On 15 d and 31 d,all piglets were food deprived for 12 h before blood samples were obtained from the precava vein.After piglets were anesthetized by electric shock and then euthanized by exsanguination,the jujunal mucosa and caecum and colon content were carefully collected.(1)Contaminated maize significantly increased the serum DAO activity on day 31 compared to the control group(P<0.05).However,supplementation with 0.2%nutritional compound additive significantly decreased the serum DAO activity(P<0.05),up-regulatedthe mRNA expression of occludin,ZO-1 and SLC7A1 in jejunal mucosa compared to the contaminated maize group(P<0.05).(2)Contaminated maize significantly increased the level of MDA(P<0.05),decreased T-AOC,SOD and GSH-px activities in jejunal mucosa compared to the control group(P<0.05).Supplementation with 0.2%nutritional compound additive signigicantly decreased the level of MDA(P<0.05),incresed GSH-px activity(P<0.05)in jejunal mucosa compared to the contaminated group.(3)Contaminated maize significantly decreased the number of total bacterias in caecum and colon content and the number of Lactobacillus in caecum content compared to the control group(P<0.05).There was no significant effect of additive supplementation and mycotoxin challenge on the number of Lactobacillus and total bacterias(P>0.05).Collectively,these results indicated that dietary mycotoxins increased the intestinal permeability,and decreased the antioxidant capacity of jejunal mucosa and the number of Lactobacillus in caecum and colon content.Meanwhile,dietary supplementation with 0.2%nutritional compound additive can alleviate the damage of jejunal mucosal structure in piglets fed mold-contaminated feeds,in a certain degree.Experiment 2 Protective Effects of Compound Additives on Growth Performance and Gut Health in Piglets Challenged with Feed Contaminated with MycotoxinsThis experiment was conducted to study the protective effects of three compound additives on growth performance,jejunal mucosal structure and function and the number of bacterias in caecum and colon content in piglets challenged with feed contaminated with mycotoxins.Thirty DLY piglets were randomly allocated to control group,contaminated feed group(rice meal fermented with Asergillus flavus and naturally contaminated maize are the sources of mycotoxins in current study,the concentration of AFB1 and FUM in the diet are 218.1 p,g/kg and 592.1 ?g/kg respectively),contaminated feed+0.3%antioxidant group,contaminated feed+0.3%intestinal nutrition agent group,contaminated feed+0.3%mycotoxin absorbent group,with 6 replicates per treatment and 1 piglet per replicate.The trial lasted for 29 d.On 15 d and 30 d,blood samples were obtained from the precava vein.On 30 d,after blood sampled,piglets were anesthetized and jujunal mucosa and caecum and colon content were carefully collected.(1)Contaminated diet significantly increased F/G compared to the control group(P<0.05).Supplementation with intestinal nutrition agent significantly inhibited the change of F/G induced by contaminated diet(P<0.05).The antioxidant or mycotonxin absorbent group had a numerical decrease in F/G compared to the contaminated diet group(P>0.05).(2)Contaminated diet significantly enhanced the serum DAO activity on day 15 and day 30 compared to the control group(P<0.05).The addition of antioxidant and intestinal nutrition agent markedly reduced serum DAO activity compared to the contaminated group on day 30(P<0.05).No significant effect of mycotoxin absorbent on serum DAO activity was observed(P>0.05).Contaminated diet significantly down-regulated the mRNA expression of ZO-1 and SLC7A1 in jejunal mucosa compared to the control group(P<0.05).The addition of antioxidant significantly up-regulated the mRNA expression of ZO-1 and SGLT1(P<0.05)and numerically improvement of the mRNA expression of SLC7A1(P>0.05)in jejunal mucosa.Supplementation with intestinal nutrition agent markedly up-regulated the mRNA expression of ZO-1(P<0.05),meanwhile,it had a numerical improvement in the mRNA expression of SGLT1 and SLC7A1(P>0.05)in jejunal mucosa.Supplementation with mycotoxin absorbent trended to up-regulated the mRNA expression of ZO-1 and SLC7A1 compared to contaminated diret group(P>0.05).(3)Contaminated diet markedly increased the number of Escherichia coli in caecum and colon content and the number of total bacterias in caecum content compared to the control group(P<0.05).The addition of antioxidant and mycotoxin absorbent resulted in a numerical decrease in the number of Escherichia coli in caecum and colon content(P>0.05).Supplementation with intestinal nutrition agent significantly decreased the numberof Escherichia coli in colon content(P<0.05)and trended to decrease the number of Escherichia coli in caecum content(P>0.05).(4)Contaminated diet significantly increased the level of MDA,however,decreased T-AOC and SOD activity in jejunal mucosa compared to the control group(P<0.05).The addition of antioxidant significantly decreased the level of MDA(P<0.05),increased T-AOC and SOD activity(P<0.05).Supplementation with intestinal nutrition agent significantly decreased the level of MDA(P<0.05),increased T-AOC,SOD and GSH-px activities(P<0.05).Supplementation with mycotoxin absorbent significantly decreased the level of MDA(P<0.05),trended to increase SOD and GSH-px activities in jejunal mucosa compared to the contaminated diet group(P>0.05).(5)Contaminated diet significantly decreased anti-inflammatory cytokine IL-10 level(P<0.05),however,increased inflammatory cytokine TNF-a level(P<0.05)and up-regulated the mRNA expression of NF-?B and TNF-a in jejunal mucosa compared to the control group(P<0.05).The addition of antioxidant significantly decreased the IL-1?,IL-6 and TNF-a levels(P<0.05),meanwhile,down-regulated the mRNA expression of NF-?B,IL=1? and TNF-a(P<0.05).The addition of intestinal nutrition agent significantly decreased TNF-? and IL-1? levels(P<0.05)and down-regulated the mRNA expression of NF-?B,IL-1?,IL-6 and TNF-a(P<0.05).Supplementation w:ith mycotoxin absorbent significantly decreased IL-1?,IL-6,IL-10 and TNF-a levels as well as the mRNA expression of NF-?B,IL-1?,IL-6 and TNF-a in jujunal mucosa compared to the contaminated diet group(P<0.05).(6)Contaminated diet significantly increased the percentage of TUNEL-positive cells(P<0.05)and up-regulated the mRNA expression of Bax in jejunal epithelial cells compared to control group(P<0.05).Adiministration with three additives protectively dereased the percentage of TUNEL-positive cells and down-regulated the mRNA expression of Bax and Caspase 3 compared to the contaminated diet group(P<0.05).Collectively,these results showed that dietary mycotoxins enhanced F/G in piglets,disturbed jejunal mucosal physical barrier,amino acid transfer function and antioxidant capacity.Furthermore,it induced the apoptosis and inflammation in jejunal epithelial cells and increased the number of Escherichia coli in caecum and colon content.Supplementation with compound additives could significantly alleviate the mycotoxicosis.Dietary supplementation with 0.3%antioxidant can effectively alleviate the damage of jejunal mucosal physical barrier,amino acid transfer function,antioxidant capacity,epithelial apoptosis and inflammation in piglets fed mold-contaminated diet.The addition of 0.3%intestinal nutrion agent protectively improved the F/G and mucosal physical barrier,decreased the number of Escherichia coli in colon content,alleviated the inflammation,oxidative stress and apoptosis in jejunal mucosa.Supplementation with 0.3%mycotoxin absorbent revealed a significant improvement in apoptosis and inflammatory reaction in jejunal mucosa induced by mycotoxins.