Document Type : Research Paper
M. Sc. Student, University College of Agriculture & Natural Resources, University of Tehran, Karaj, Iran
Professor of Poultry Science, University College of Agriculture & Natural Resources, University of Tehran, Karaj, Iran
Associate Professor of Poultry Science, University College of Agriculture & Natural Resources, University of Tehran, Karaj, Iran
The aim of this research was to determine effects of different levels of all-trans-retinol acetate on immunity performance of broiler breeder roosters and also to find the level with most immunity performance. * Treatments were consisted of 5 level all-trans-retinol acetate (0, 6000, 12000, 18000, 24000 IU/kg) added to basal diet. * 60 broiler breeder roosters were used from 45 to 48 weeks of their rearing period in a completely randomized design with 12 replicates per treatment. * Cell immune system response was measured by PHA-P sensitivity and blood immunity was measured by antibody titr against SRBC. * Titr of antibody against SRBC was affected by retinol acetate level (P<0.05) and blood immunity repose was increased by increasing level of retinol acetate. * Highest and lowest blood immune responses belong to 24000 and zero IU/kg treatments respectively (P≤0.03). * Increasing level of retinol acetate increased IgM (P≤0.04). * The results of cutaneous sensitively showed increasing effect of retinol acetate till 18000 IU/kg (P<0.05). * The results of this research showed that 18000 Iu/kg of retinol acetate resulted in best level of immune system in broiler breeder roosters, and this amount is higher than suggested amount by ROSS 308 catalogue.