Effects of Supplementation of Broiler Diets with Fish Oil and Linseed Oil on Growth Performance, Cytokines, and Cecal Histopathological Changes in Broiler Chickens Infected by Eimeria tenella

Avian coccidiosis is one of the serious infectious diseases affecting poultry, caused by different species of genus Eimeria. The present study was designed to evaluate the impacts of supplementation of broiler diet with Fish Oil (FO) or Linseed Oil (LO) at 3 and 5% on growth performance, hematological parameters, cytokines, antioxidant capacity, fecal oocysts count, and cecalhistopathoogical changes of broiler chickens infected by Eimeria tenella . One hundred eighty 1-day old Cobb chicks were randomly allocated to 6 groups (30 chicks each). Each treatment was replicated 3 times with ten chicks (n-10). The experimental ( ioscaloric- isonitrogenous ) diets were based on corn-soybean meal with 3% corn oil (positive and negative control), FO at 3 and 5% and LO at 3 and 5%. Chickens were inoculated by gavage with 40,000 sporulated oocysts at 21 days of age. Feeding diets supplemented with 3 and 5% LO resulted in higher body weight and body weight gain than those fed FO supplemented diets or positive control group. Diets supplemented with 5% FO or 5% LO significantly (p< 0.05) reduced cecal lesions and parasitic density scores caused by E.tenella . Dietary supplementation of 3% LO significantly (P<0.05) decreased the fecal coccidial oocysts count through 12 days post coccidial infection followed by 5% LO supplementation compared with those of the broilers fed the negative control diet and other treatment groups. Hematological parameters, Red Blood Cell count (RBCs), Packed Cell Volume (PCV), blood hemoglobin (Hb) were significantly decreasedin the positive control. However, there were no significant differences in hematological parameters between negative control and other experimental groups.Diets supplemented with 5% FO increased plasma level of interlukine- 6 (IL-6) compared with other treatment groups, while 5% LO increased plasma level of IL-1 and tumour necrosis factor. Serum total antioxidant capacity in chickens fed diets supplemented with LO (3% and 5%) were higher than other groups. In conclusion, supplementation of broiler diets with 3-5% LO improved growth performance and reduced cecal lesions and fecal oocysts count and effective in controlling the adverse effects of coccidiosis with E. tenella .