THE EEFECT DIETARY VITAMIN E AND SELENIUM ON OVERALL PERFORMANCE AND IMMUNE RESPONSE OF BROILERS FED EITHER BASAL OR OXYTETRACYCLINE TREATEDILERS

The impact of dietary vitamin E-selenium on overall performance and immune response of broiler chickens fed either basal or oxytetracycline diet was studied. Four groups of day old broiler chicks, 35 of each, were used. Group I fed on basal diet treated with oxytetracycline at a ratio of 0.2 g/kg, while birds of group 2 received basal diet supplied with vitamin E and selenium at a level of 300 mg/kg and 0.25 ppm respectively. The birds of group 3 fed on basal diet provided with a combination of both oxytetracycline (02 g/kg) and vitamin E-selenium (300 mg and 0.25 ppm). Group 4 fed on basal diet and kept as untreated negative control. All groups were vaccinated against Newcastle disease using live vac- cines. The experimental period extended for 35 days. Body weight development and feed conversion rate were recorded weekly. Individual blood samples were collected weekly to be subjected to Newcastle antibody ELISA titration. Oxytetracycline had a growth promoting effect in treated birds as compared with the untreated control group. Dietary vitamin E-selenium had a superior effect on body weight development as compared with either oxytetracycline treated or untreated control groups. Oxytetracycline had an immuno- suppressive effect as detected by Newcastle dis- ease ELISA antibody titres. Dietary vitamin E- selenium could compensate neutralizing the immunosuppressive effect of oxytetracycline that could be applied in broiler production practice.