Effects of cold stress on mRNA expression of immunoglobulin and cytokine in the small intestine of broilers

To investigate the effects of cold stress on mRNA expression of immunoglobulin and cytokine in small intestine of broilers, eighty-four 15-day-old male chickens were randomly divided into 12 groups. There were 1 control (25 °C) and 5 acute stress groups (under the temperature of 12 ± 1 °C) for 1, 3, 6, 12 and 24 h, 3 control (25 °C) and 3 chronic cold stress groups (under the temperature of 12 ± 1 °C) for 5, 10, and 20 d. The mRNA expression levels of IL-2, IL-4, IL-7, IL-10, IL-17, IFN-γ, IgA, IgM, IgG, plgR, and TGF-β4 in duodenum, jejunum and ileum were detected by real-time PCR. The results showed that expression levels of IgM, IgA, IgG, plgR and IL-7 had an increased tendency in acute and chronic cold stress, especially plgR that was markedly increased in the duodenum than jejunum and ileum in the acute cold stress. In addition, the mRNA expression levels of IL-2, IFN-γ, IL-4, IL-17 and TGF-β4 had a first increased then decreased tendency in acute and chronic cold stress groups, however, expression levels of IL-4 were higher in the stress groups than control groups. The histopathological detect showed that issues in cold stress group was seriously injured. These results demonstrated that cold stress could cause the change of immune function in chicken intestinal.