Expression analysis of IFN-γ, IL-2 and IL-13 genes in Thymus tissue of broiler chickens fed with different levels of oak acorn

Today, the use of native feeds such as oak acorn, in order to replace with corn, in the diet of broiler chicken has been considered by the breeders of this industry. Oak acorn contains significant amounts of phenolic compounds such as tannins. Consumption of feeds containing phenolic compounds can affect the genes expression levels of immune system. Therefore, the aim of this study was to investigate the effects of different levels of oak acorn on expression of interferon gamma, interleukine-2 and interleukine-13 genes in thymus tissue of broiler chickens. In this experiment, three different diets (without oak, diet contains 15% and 20% oak acorn) used for feeding broiler chickens during the 42-day period. At 42 days of age, the total RNA was extracted from thymus tissue of 18 broiler chickens (6 chickens per treatment) and the expression of IL-2, IL-13 and IFN-γ genes was evaluated and compared with the beta-actin reference gene. REST, 2009, V2.0.13 software was used for analysis of gene expression data. The results showed that the expression levels of IL-2 and IL-13 genes were significantly higher in 15% oak acorn in compared to control treatment (P <0.05) but in 20% treatment oak acorn, no significant different was found in mRNA levels of IL-2 and IL-13, while expressions of two genes in compared to 15% oak acorn were significantly lower (P <0.05). According to the results of this study, it seems that consumption of oak acorn in broiler chicken diets at low levels can be observed to increase of the immune system ability in thymus tissue, but increasing the amount of oak acorn could led to suppress of expression IL-2 and IL-13 genes in thymus tissue of broiler chickens.