الملخص
The study was conducted on 147 birds and distributed into seven groups, each group consisted of 21 birds. For the first, second, third and fourth groups, a black seed(Nigella Sativa) was added at a ratio of (1, 0.75, 0.5, 0.25)%, respectively, while an anti-coccidiosis (salinomycin) was added to the fifth group at the rate of 0.05% in order to compare its effect with the black seed. As for the sixth and seventh groups, they remained without adding a black seed or an anti-coccidiosis. At the age of 15 days, the first six groups of birds were given the challenge dose (2.6 x104) sporulated oocysts / bird orally of E.tenella. The results of the experiment showed that adding the black seed by 0.5% to the diets of infected bridler chickens led to a significant increase in the average of bird weight and the feed conversion ratio, and the percentage of safety was (67%)and the index of effectiveness of Anticoccidial was moderate compared to rest of the experimental groups, while the indicator of oocysts excretion was 20 in the groups with a black seed added at rates of (0.75, 0.25%) as well as in the fifth group with an anti-coccidiosis, and the percentage of mortality was 9% in the groups of an added black seed at the rate of (0.75, 0.5. 0.25)%.