The Effect of Different Levels of Zinc and Selenium Supplementation in Diets Containing Oxidized Oil on Immune System and Lymphatic Organs of Broiler Chickens

In order to study the effect of different levels of zinc and selenium in diets containing oxidized oil on humoral and cellular immunity and relative weight of lymphoid organs in broilers, an experiment performed in a 2×3×2factorial arrangement in a completely randomized design(two Zero and 2% oxidized oil levels, three levels of 0, 40 and 100 mg / kg zinc sulfate, two levels of zero and 0.3 mg / kg selenium) using 480 one-day-old Ross 308 chicks with 12 treatments and 4 replicate per treatment  and 10 chicks per each treatment. To evaluate the immune system, changes in antibody titers were performed by injection of Sheep red blood cell (SRBC) at two times (21 and 28 days) and blood sampling at two times (28 and 35 days). The relative weights of bursa, spleen and thymus were measured at 42 days after slaughter. Cutaneous basophil hypersensitivity (CBH) test was used to evaluate cellular immune system. The results of total antibody titer in first and second times showed significant difference (P <0.05). Maximum grade of primary and secondary total antibodies in chicks fed with 100 mg / kg zinc and 0.3 mg / kg selenium and chicks oil). Containing 100 mg / kg zinc and 0.3 mg / kg selenium and the effect of zinc, Selenium, and their combined supplementation on the initial total antibody grade response was also significant, with 100 mg / kg zinc and 0.3 mg / kg. Selenium significantly increased the initial total antibody titer response. The effect of different experimental groups on IgM antibody response was significant at the first and second time (P <0.05). The cellular immune response of CBH test was not affected by different experimental diets. The effect of treatments on the relative weight of different lymph nodes was not significantly different. The results demonstrated that supplementation of zinc sulfate and sodium selenite improved the immune system of broilers.