In ovo vaccination of chicken embryos with viral vaccines containing multiple agents

Broiler chickens are the largest segment of poultry industry.Therefore, disease prevention by vaccination is an integral part of flock health management protocols. Marek’s disease, a lymphoproliferativedisease of chickens causes sever death losses and condemnation inunvaccinated susceptible chickens. Also Newcastle disease continues tohave essential economic impact on the poultry industry throughout theworld. In ovo vaccination procedure is relatively new at the present timeand it may be used alternative to conventional method of vaccination tovaccinate broiler chickens.This study aimed to evaluate the value of in ovo vaccination inprotection of chickens against Marek’s disease (MD) and Newcastledisease (ND) viruses.In this study the following were done.The first experiment, which was done to evaluate the immuneresponse against Newcastle disease virus (NDV), Hitchner B 1 strain(HB1) vaccine alone or combined with Marek’s disease virus vaccme(MDVV); herpes turkey virus (HVT) vaccine through embryovaccination (EV) during early {loth emberyonated date (ED)} and late{18th emberyonated date (ED)} stages of embryonation. The highestNewcastle disease( ND) virus-ID antibody titer was achieved whenNewcastle disease virus vaccine (NDVV) was embryo vaccinated (EV)alone at 18th ED.and it was (9 log 2).The second experiment, which was done to compare the immuneresponse between inoculation of Marek’s disease virus vaccine (MDVV)