ABSTRACT
In this experiment, the effect of consecutive oral levamisole usage on cellular and humoral responses of broilers immune system was evaluated. The aim of this experiment was to determine the best level of levamisole for stimulating immune system of broilers. The experiment was conducted by 250 day old [male and female] broiler [Ross] chicks with an average live weight of 40.2g. Effect of zero [control L0], 3.5 [L3.5], 7 [L7], 14 [L14] and 28 [L28] mg/l of levamisole in drinking water from 5 to 25 days under randomized design using a factorial experiment with 5 replication were studied. Cellular immune responses were assayed by PHA-P injection in the skin fold of wings [day 15] and thickness of skin were measured after 24 and 48 hours. Sheep Red Blood Cell [SRBC] 25% were injected in the breast muscle in days 7 and 21 to investigate humoral immune responses, and IgG titer against SRBC was determined in days 7, 14, 28, 35, and 42 by agglutination test. Cellular immune responses to PHA-P in treatments containing 7 and 14 mg/l of levamisole [0.272 and 0.205, respectively] were significantly affected [p<0.05]. IgG titer against SRBC in treatment containing 14 mg/l of levamisole [6.16] was significantly higher than other groups [p<0.05]. Carcass trait of broiler chicks were not affected by different level of consecutive oral levamisole [p>0.05]. The low level [up to 14 mg/L] of consecutive oral levamisole promotes cellular and humoral immune system responses of broiler chicks
Subject(s)
Animals , Chickens , Immunity, Humoral , Immunity, Cellular , Immune SystemABSTRACT
Biosecurity in the production of broiler chickens is very important but it is hard or even impossible to maintain; hence, promotion of immune responses could control diseases in chickens. At present study, the effect of six levels of oil-extracted propolis [0, 50, 100, 150, 200 and 250 mg/kg ration] on immune system against Newcastle virus was studied using a completely randomized design with 360 chickens. Blood antibody ratio against the Newcastle virus [HI test], the weight of thymus, bursa fabricius and the percentage of lymphocytes were measured for a period of 42 days and the data were analyzed. The results indicated that the rate of antibody has significantly [p<0.05] increased with an increase in the amount of propolis in diets and with the levels of 250 mg/kg ration the antibody rose to 10.42 titre at the age of 42 compare to control [6.42]. The weight of thymus gland also increased significantly [p<0.05] with the increase in the levels of propolis and at the levels of 250 mg/kg in ration, weight of thymus increased up to 14.54g in compared to control [8.47 g]. Similarly the weight of bursa fabricius significantly increased [p<0.05] from 2.42 g in contral to 4.62 g in 250 mg propolis/kg of ration [p<0.05]. Intake of 200 and 250 mg propolis/kg of ration has significantly increased the lymphocytes to the levels of 50.18 and 51.25 percent compared to the control [48.93%], respectively. Results indicate that the efficiency of immune-system for immunizing of broiler chickens against Newcastle virus has been promoted using 50 up to 250 mg of propolis per kg of ration