Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 8 3 2013 09 15 474 480 EN Sobhan Sajadifar Department of Epidemiology and Parasitology, Faculty of Veterinary Medicine and Zootechnics, Armenian National Agrarian University, Yerevan, Armenia. Hadi Miranzadeh Department of Veterinary, University of Applied Science and Technology, Institute of Science Applied Higher Education of Jahad -e- Agriculture, Isfahan, Iran. Milad Moazeni Department of Veterinary, University of Applied Science and Technology, Institute of Science Applied Higher Education of Jahad -e- Agriculture, Isfahan, Iran. 2015 10 14   Background: The aim of the present study was the comparison of humoral and cell-mediated immunity in broilers fed with different levels of zinc during a coccidiosis challenge. Methods: One hundred and forty- four one-day-old broiler chicks were used with three dietary zinc (40, 120 and 200 mg/kg). At 14 d of age, all birds were inoculated orally with 5×103 sporulated oocysts of E. Tenella. At 2, 22, 32, 42 days of age, the blood serums were tested for antibody titer against New-castle disease vaccine, using the standard HI test. On day 42 the sum of ni-trite and nitrate based on the reduction of nitrate to nitrite by cadmium and white blood cell count (WBC) using a hemocytometer were measured. Results: At 42 d, levels of 120 and 200 mg significantly (P< 0.05) increased the antibody titer in compare with the control. The peak response of CBH was observed at the level of 200 mg Zn/kg diet. Also both level of 120 and 200 mg Zn/kg diet increased WBC count and sum of nitrite and nitrate in serum compared with the control. Conclusion: The levels of 120 and 200 mg Zn/kg diet could be considered as a non-pharmacologic booster of immunity in broilers chicks infected with E. Tenella. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/467 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/467/500