Abstract

The present study was carried out to discover the protective and curative effects of alcoholic extracts of garlic (Allium sativum) and black seeds (Nigella sativa) in rabbits experimentally infected by Eimeria magna using in vivo, in vitro, and histopathological examination. Overall oocysts number per gram was significantly lower in the garlic treatment and pretreatment groups, compared to the control positive, sulfadimidine treatment, and black seed treatment groups. At the end of the experiment, the oocyst disappeared in garlic pretreatment, garlic treatment, and black seed pretreatment groups. While oocyst counts of control positive and sulfadimidine groups were increasing oocysts similarly at the end of the experiment with repeated cycles. In vitro sporulation inhibition of garlic extract showed significant efficacy on E. magna oocysts in comparison with black seed extract and high significant efficacy of sporulation inhibition, compared to sulfadimidine. While black seed extract showed high significant efficacy of sporulation inhibition, compared to sulfadimidine. Body weight gain increased in control negative, garlic pretreatment, and garlic treatment groups in comparison with other groups. The results showed that there were no significant differences in erythrocytes counts in all experimental groups while leukocyte counts showed a significant decrease in control positive and sulfadimidine groups, compared to the other groups. Similarly, the histopathological examinations on days 14 and 28 post-infection revealed pathological changes in intestinal villi of the control positive group that appeared thickened and deformed with hypertrophied enterocytes containing numerous developmental stages of E. magna. Both garlic and black seed extract had beneficial effects on improving the lesions grossly and microscopically. The results obtained in the present study proved that garlic pretreatment had a better effect on a prophylaxis and treatment for coccidiosis than garlic treatment and both had more beneficial effects, compared to black seed extract. Therefore, it is recommended to use garlic as a natural feed additive in rabbit feeding as a prophylaxis and treatment for coccidiosis to minimize the economic losses caused by this parasite.