Although anticoccidial drugs have been used to treat avian coccidiosis for nearly a century,
resistance, bird harm, and food residues have caused health concerns. Thus, Nannochloropsis
oculata was investigated as a possible coccidiosis treatment for broilers. A total of 150
1-day-old male Cobb broiler chicks were treated as follows: G1-Ng: fed a basal diet; G2-Ps:
challenged with Eimeria spp. oocysts and fed basal diet; G3-Clo: challenged and fed basal
diet with clopidol; G4-NOa: challenged and fed 0.1% N. oculata in diet, and G5-NOb:
challenged and fed 0.2% N. oculata. Compared to G2-Ps, N. oculata in the diet significantly
(P < 0.05) decreased dropping scores, lesion scores, and oocyst shedding. Without affecting
breast meat colour metrics, N. oculata improved meat quality characters. At 28 days of age,
birds received 0.2% N. oculata had significantly (P < 0.05) higher serum levels of MDA, TSOD,
HDL, and LDL cholesterol compared to G2-Ps. Serum AST, ALT, and urea levels were all
decreased when N. oculata (0.2%) was used as opposed to G2-Ps. Histopathological
alterations and the number of developmental and degenerative stages of Eimeria spp. in the
intestinal epithelium were dramatically reduced by 0.2% N. oculata compared to G2-Ps.
Molecular docking revealed a higher binding affinity of N. oculata for E. tenella aldolase,
EtAMA1, and EtMIC3, which hindered glucose metabolism, host cell adhesion, and invasion
of Eimeria. Finally, N. oculata (0.2%) can be used in broiler diets to mitigate the deleterious
effects of coccidiosis.