عنوان مقاله [English]
The aim of this study was to compare the performance of immune system in Arian, Native, Arian × native crosses, native × Arian crosses and Ross chickens. Through artificial insemination, a total number of 298 birds produced and reared with 100 Ross strain chickens. Thereafter, 15 to 20 percent of chickens were randomly chosen for immune system performance and some of blood parameters comparison. The studied traits were humoral, cell-mediated and innate immunity responses, plasma protein concentrations and relative weight of lymph organs. Data were analyzed using GLM procedure and means were compared using Tukey method. The highest titer of total antibody was in Arian strain and the lowest was in Ross strain. There was no significant difference between sexes and strains for cell-mediated immunity. Responses in crossbred chickens for humoral and cell-mediated immunity were not significantly different from Ross strain. No significant difference was observed for hematocrit percent between crossbred chickens and commercial strains. In crossbred chickens, the percentage of plasma albumin was significantly higher than the other strains (P<0.05). While, the lysozyme activity of crossbred chickens was significantly lower than Arian strain (p<0.05), it did not indicate any difference with Ross strain. The relative weight of all organs in crossbred chickens was lower than native and higher than commercial chickens. The results of current study indicated that the performance of immune system in crossbred chickens was favorable and in some cases better than the other strains. Therefore, it is possible to create resistance birds with suitable growth performance from crosses of native and commercial strains.