This experiment was conducted to evaluate the effect of different levels of Nigella sativa meal (NSM) on performance, immunity and some blood biochemical and hematological parameters of broiler chicks. A total of 120, one day-old broiler chicks (Hubbard) were divided into four treatment groups, with three replicates per treatment and 10 chicks per replicate. Chicks in control group were fed basal diet. Birds in treatment groups were fed on diets supplemented with 3, 6 and 9% NSM. Body weights of broilers were measured at one, 21 and 42 days, feed intake was measured at the same periods and feed conversion was calculated, accordingly. Blood samples of three birds per replicate were collected at 30 and 42 days of age from wing vein were taken for biochemical and hematological analysis. At ages 30 and 42 days, two chicks (one male and one female) were taken randomly from each replicate and slaughtered and the spleen, thymus and bursa were separated and weighted. Results of this experiment showed that, supplementing 3 and 6% of NSM improved body weight gain (BWG) and feed conversion ratio (FCR) of broilers at starter and grower periods (P<0.05), and also increased serum albumin levels (P ≤ 0.05). Total protein and glucose levels were not statistically (P ≥ 0.05) influenced. Supplementing 3 and 6% N. sativa meal decreased serum triglyceride and plasma cholesterol had lower level in all treatments compared with control. In addition, HDL fraction was increased and LDL fraction was decreased in all treatments compared to control group. Birds fed NSM except 9% insignificantly improved spleen percentage and improved significantly bursa and thymus percentages compared with control group. Plasma AST and ALT decreased with all levels of NSM and could suggest that has properties to enhance liver health.

In conclusion, results of this study showed that addition of 3 and 6% of NSM seem to have a positive influence on growth performance, blood biochemical, immune-responsiveness and economic efficiency and it could be considered growth promoter for broiler chicks