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The purpose of this study was to investigate whether dietary supplementation with glutamic acid has beneficial effects on growth performance,intestinal morphology and histology,and intestinal amino acid transporters in growing swine fed mold-contaminated feed.Fifteen pigs (Landrace×Large White) with a mean body weight (BW) of 55 kg were randomly divided into control group,myxotoxin group and glutamate group and each group has 5 pigs and were fed basal feed,contaminated feed and 2% glutamic acid+ contaminated feed respectively.The ADG in the mycotoxin group was significantly less than that in a control group and supplementation with glutamic acid helped protect against these adverse effects.After pigs were exposed to contaminated feed,both the villus height and crypt depth in the ileum and jejunum were increased and villi were scattered and desquamated.The number of goblet cells in the jejunum and ileum was significantly decreased.Furthermore,the DAO level,and especially the D-lactate level were increased.In the glutamate group,the ileal crypt depth and jejunal villus height were reduced and the villi were larger in both the jejunum and ileum.Meantime,the number of goblet cells in the jejunum was increased.Supplementation of contaminated feed with glutamic acid notably decreased the serum D-lactate level.Furthermore,while theserum amino acid composition was modified in the mycotoxin group,these changes could be partially restored when contaminated feed was supplemented with glutamic acid.The mRNA levels of CAT1,y+ LAT1,y+ LAT2 and EAAC1 in the ileum were down-regulated in the mycotoxin group compared with those in the control group.However,there were no differences in gene expression between the glutamic acid group and the mycotoxin group in the ileum and jejunum.These results suggest that mycotoxin-contamination can dramatically impair not only growth performance and the morphology and histology of the intestine,but also intestinal amino acid transporters.However,supplementation with glutamic acid can reduce this impairment induced by mycotoxins.In conclusion,glutamic acid can act as a nutritional regulating factor to reduce the adverse effects induced by mycotoxins.