Immune response and enzymatic activities of broiler chicks under cold stress to nitroglycerin

This experiment was conducted to evaluate the effect of addition of a nitroglycerin (NG) slow release drug on prevention of ascites syndrome in broiler chickens. A total of 500 broiler chicks at 7 days of age were used in a completely randomized design with 5 treatments, 5 replicates and 20 chicks per each replication. The experimental treatments included: 1) positive control group (without induction of ascites and without addition of NG); 2) negative control group (induction of ascites without adding NG, treatments 3, 4 and 5, including induction of ascites with 5, 10 and 20 mg/kg NG in diet, respectively. In order to induce cold stress, the temperature was fixed at 15oC from 15 until 42 day of age. The humeral and cellular immune responses as well as blood serum enzyme concentrations were evaluated. The results showed that cold stress significantly reduced the relative weights of spleen and thymus (p < 0.05) but had no significant effect on relative weight of bursa of Fabricius. The utilization of NG significantly increased the relative weights of Spleen and thymus (p < 0.05). The immunoglobulin M response and cutaneous basophilic sensitivity decreased as a result of cold stress, and significantly increased by using NG (p < 0.05). The concentration of AST and LDH enzymes increased as a result of cold stress and the utilization of 20 mg/kg of NG in the diet significantly decreased them (p < 0.05). The lipid peroxidation index improved near meaningfully as a result of using NG (P= 0.06)