Effects Of Low Dose Of Deoxynivalenol And Zearalenone On Intestinal Health Of Piglets

Common fusarium toxins include deoxynivalenol(DON)and zearalenone(ZEA),which are widespread in nature and extremely harmful.When mycotoxins enter the animal's body,the intestinal epithelium becomes the first barrier against harm.In animal species,the digestive system of pigs is similar to that of humans.Therefore,pigs can be used as a model for evaluating mycotoxins and human intestinal health.However,the effects of low doses of DON and ZEA in contaminated diets on intestinal inflammation and epithelial barrier function of piglets need to be studied.Therefore,this project chooses piglets to study the effects of DON and ZEA in naturally moldy diets on piglets growth performance and intestinal health,and provides a theoretical basis for evaluating the effects of DON and ZEA on animal and human health.In this study,a total of 80 piglets were weaned at 21 day and then were randomly divided into 4 groups,with 5 replicates in each group,and 4 piglets in each replicate.Piglets were submitted to a two phase experiment.The first phase was an intoxication period(21?42 days)with pigs fed 4 diets: control diet(CON),DON diet(1000.6 ?g/kg),ZEA diet(269.1 ?g/kg),and D+Z diet(1007.5+265.4 ?g/kg).The next phase was a recovery period(43?56 days)in which pigs were fed a CON diet.The main findings are as follows:1.Effects of combined DON and ZEA in naturally moldy diets on growth performance of piglets.During the mycotoxin exposure period,the body weight gain(BWG)and the average daily feed intake(ADFI)of piglets in the DON and ZEA treatment groups showed no significant(P > 0.05)differences from those in the CON group,while the BWG and ADFI in the D+Z group significantly(P < 0.01)lower than the CON group.During the recovery period,there was no significant(P > 0.05)difference between BWG and ADFI among the 4treatment groups.2.Effect of combined DON and ZEA in naturally moldy diets on systematic and intestinal inflammation of piglets.During the mycotoxin exposure period,DON or ZEA contaminated diets significantly(P < 0.01)increased serum TNF-?,IL-1?,and IL-6 levels compared with the CON group.The serum levels of TNF-?,IL-8,and IL-6 in piglets in the D+Z group were significantly higher(P < 0.01)than those in the DON and ZEA groups.Similar to the pro-inflammatory cytokines in the serum,the contents of TNF-?,IL-8,and IL-6 in the jejunum were significantly(P <0.05)higher in the DON,ZEA and D+Z groups than in the CON group.In addition,the DON,ZEA,and D+Z groups increased the gene expression of pro-inflammatory cytokines in the jejunum.These results showed that mycotoxin exposure significantly induced gut inflammation especially in diet containing both mycotixins.During the recovery period,piglets fed DON or ZEA contaminated diets had significantly(P < 0.05)higher serum IL-1? levels than the CON group,and other pro-inflammatory cytokines in the serum and intestine showed no significant(P > 0.05)differences among those 3 groups.While,contents of TNF-? and IL-6 in the serum and the jejunum,and m RNA expression levels in the D+Z group were still significantly(P < 0.05)higher than the same in the CON group.These data indicate that dietary D + Z exposure in early life can have a long lasting impact on intestinal inflammation.3.Effect of combined DON and ZEA in naturally moldy diets on the intestinal epithelial barrier and populations of selected bacteria in the digesta of intestine of piglets.In terms of intestinal epithelial barrier function: during the mycotoxin exposure period,piglets exposed to DON,ZEA,and D+Z contaminated diets significantly(P < 0.05)decreased the protein expression levels of claudin-4 in the jejunum.The ZEA and D+Z groups significantly(P < 0.05)decreased the protein expression of E-cadherin compared with the CON group.In the recovery period,the protein expression of claudin-4 in the jejunum of the DON,ZEA,and D+Z groups were still significantly(P < 0.05)lower than the CON group.These results provide evidence that ZEA and DON impaired the intestinal epithelial barrier function,and could not recover within 2 weeks.In terms of populations of selected bacteria in the digesta of intestine:compared with the CON group,the DON,ZEA,and D+Z groups all significantly(P < 0.01)increased the number of E.coli in the cecum,and all significantly(P < 0.01)reduced the number of Lactobacillus and Bifidobacterium in the cecum.In addition,the changes in the number of the above mentioned bacteria in the D+Z group were significantly(P < 0.01)higher than the DON and ZEA group.During the recovery period,the number of Bifidobacterium in the DON,ZEA,and D+Z groups returned to normal levels,but the number of Lactobacillus in the cecum was still significantly(P < 0.01)lower than that in the CON group.In addition,the number of E.coli in the cecum of the D+Z group was still significantly(P <0.01)higher than that of the CON group.It shows that feeding DON and ZEA contaminated diets can change the number of specific microbes in the intestine of piglets,and DON and ZEA have a synergistic effect in perturbing the cecum microbiota profile..This study not only evaluates the toxic effects of DON and ZEA and provides basic data for establishing limit standards of DON and ZEA in piglets feed,but also provides more sensitive biomarkers to which DON or ZEA may be involved in the development of diseases in animals and humans.