Thesis:

Investigation of the Role of iron on the Immune system and Performance of Broiler Chickens

Iron, as a highly valuable mineral, has long been of great interest in human medicine, veterinary science, and animal nutrition. This essential element plays significant roles in enhancing growth performance, strengthening the immune system, improving eggshell quality, reducing feed conversion ratio (FCR), lowering mortality rates, and numerous other applications. To investigate the role of iron on immune response and performance of broiler chickens, a total of 400 Ross 308 broiler chicks were selected from a commercial poultry farm in Sabzevar. The experiment was conducted in a completely randomized design with four dietary treatments differing in iron levels. Each treatment included five replicates with 20 mixed-sex chicks per replicate, and the trial lasted for 42 days. The experimental treatments consisted of one control group and three groups receiving additional iron in their diets. The basal diet contained 60 mg/kg of iron, considered the control. The other treatment groups received 80, 100, and 120 mg of iron per kg of feed, respectively. Iron was added in the form of a mineral supplement (ferrous sulfate). All diets were formulated based on NRC (2024) recommendations and were isocaloric and isonitrogenous, primarily based on corn and soybean meal. Measured parameters included: weekly body weight gain, feed conversion ratio, Newcastle and avian influenza antibody titers, final body weight at slaughter, mortality rate, water-holding capacity (WHC) of the breast muscle, and the relative weights of lymphoid organs and carcass components (feather and skin, thigh, breast, wing, neck, foot, liver, gizzard, lung, fat, and proventriculus). According to the results, the group receiving 100 mg/kg of dietary iron showed the highest weekly weight gain, final body weight, improved feed conversion ratio, increased weights of organs and lymphoid tissues, higher breast muscle WHC, and highest antibody titers against Newcastle and avian influenza, along with the lowest mortality rate. The poorest results were observed in the control group (60 mg/kg). The 120 mg/kg group showed moderately favorable outcomes, ranked second in most parameters. This study indicates that dietary iron supplementation can improve the immune response and performance of broiler flocks, and that optimal dosing leads to significantly better outcomes.

Keywords: Iron – Performance – Broiler Chicken – Sabzevar – Immune System