An experiment was conducted to investigate the effects of glutamine (Gln) on the lymphocyte proliferation and intestinal immune relevant gene expression in broilers infected with Salmonella Enteritidis. 240 1-day-old broilers were divided randomly into four groups in a completely randomized design, each of which had 6 replicates. Birds were reared in battery cages for 21 days. The experimental groups were as follows: control group (unchallenged group, CON), basal diet; Salmonella Enteritidis challenged group (challenged with 2.0 × 104 CFU/mL of Salmonella Enteritidis, SCC), basal diet; Gln 1, basal diet plus Salmonella Enteritidis challenged plus Gln at 0.5% diet; Gln 2, basal diet plus Salmonella Enteritidis challenged plus Gln at 1.0% diet. The results showed that Salmonella Enteritidis infection led to some decrease in the relative weight of spleen and bursa (except at 21 d), lymphocyte percentage, number of proliferation peripheral blood T and B lymphocytes, and increased the heterophil percentage, H/L ratio, mRNA expression levels of TNF-α, NF-κB p65, IL-1β, IL-6, and IL-8 in the jejunal and ileal mucosa compared with the measurements of these parameters in the CON group at d 4, 7, 14, and 21 (p < 0.05). On the other hand, chickens fed the Gln showed improved the relative weight of spleen and bursa, increased the lymphocyte percentage, number of proliferation peripheral blood T and B lymphocytes, and decreased the heterophil percentage, H/L ratio, and immune relevant gene expression in the jejunal and ileal mucosa compared with the measurements of these parameters in the SCC group (p < 0.05). These results suggest that Gln as a feed additive could be effective for reducing the detrimental effects of Salmonella Enteritidis infection, and increase the intestinal immune barrier function of broilers.
Keywords: Broiler; Cytokine; Glutamine; Lymphocyte proliferation; Salmonella Enteritidis.
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