摘要：In this study, we determined the suitability of lentogenic LaSota and naturally occurring avirulent I2 vaccine strains of Newcastle disease (ND) virus for efficacious in-ovo vaccination of broiler chickens. A total of 114 embyonated eggs divided into five groups (A, B, C, D and E) consisting of 25 eggs in each of groups A and B, 20 eggs in each of groups C and D and 24 eggs in group E were used in the study. Eighteen-day-old embryonated eggs in group A were vaccinated in-ovo with ND-I2 vaccine while the same age of embryos in group B were vaccinated with ND-LaSota. Thirteen-day-old embryonated eggs in groups C and D were vaccinated with ND-I2 and ND-LaSota respectively. Group E served as unvaccinated control. There was significant difference (p 2) used for the in-ovo vaccination were pathogenic for chick embryos, however, ND-I2 vaccine was better tolerated when administered to 18-day-old chick embryo.
