Abstract   

    A study was conducted to evaluate the utility of Marek's disease vaccination in day-old broilers reared under local conditions. Day-old broilers were vaccinated with Rispen strain vaccine, HVT or combination of HVT and Rispen and were observed for weight gain, mortality and humoral and cell mediated immune responses. Mortality rate did not differ among any of the vaccinated groups and unvaccinated controls. Marek's disease vaccination had no effect on the titre of the Newcastle disease vaccine. Similarly cell mediated immune response of different groups were also non-significant as measured by reaction to phytohaemagglutinin. The study shows that vaccination against Marek's disease in day-old broilers does not offer any advantage under local poultry farming practices.    

Key words: Marek's disease, day-old broilers, vaccination effects.