Effect of zinc on humoral and cell-mediated immunity of broilers vaccinated against coccidiosis.
Sajadifar، Sobhan نويسنده Department of Epidemiology and Parasitology, Faculty of Veterinary Medicine and Zootechnics, Armenian National Agrarian University, Yerevan, Armenia. Sajadifar, Sobhan , Miranzadeh، Hadi نويسنده Department of Veterinary, University of Applied Science and Technology, Institute of Science Applied Higher Education of Jahad -e- Agriculture, Isfahan, Iran. Miranzadeh, Hadi , Moazeni، Milad نويسنده Department of Veterinary, University of Applied Science and Technology, Institute of Science Applied Higher Education of Jahad -e- Agriculture, Isfahan, Iran. Moazeni, Milad
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.