The piglets were
housed in individual pens and orally challenged with enterotoxigenic Escherichia coli (ETEC) during the preliminary
trial period
The jejunalmorphology and histology analysiswere detected under lightmicroscope. The plasma
D-lactate and diamine oxidase (DAO) were determined by using enzymatic spectrophotometric assay.
Immunohistochemistry assays were used to examine secretory immunoglobulin (sIgA) protein expression.
Real-time PCR was used to determine mRNA levels of cytokine and Toll-like receptor 4 (TLR4) in jejunal mucosa.
The results showed that, compared with the control, dietary addition of 300 mg/kg or 400 mg/kg curcumin
decreased (P b 0.05) feed/gain ratio and crypt depth, improved (P b 0.05) villus height and villus height:crypt
depth ratio, reduced (P b 0.05) plasma D-lactate and DAO activity, up-regulated the protein expression of sIgA
(P b 0.05), increased (P b 0.05) the number of goblet cells (GCs) and reduced (P b 0.05) the number of
intraepithelial lymphocytes (IELs).