Sarma G, Greer W, Gildersleeve R P, Murray D L, Miles A M
Tri Bio Laboratories, Inc., State College, Pennsylvania 16803, USA.
Avian Dis. 1995 Apr-Jun;39(2):211-7.
The field safety and efficacy of a bivalent Marek's disease (MD) vaccine (herpesvirus of turkeys + strain SB-1) administered in ovo were evaluated. The vaccine was administered to commercial broiler chicken eggs using Embrex's INOVOJECT automated egg-injection system. Comparisons were made with a conventional method of vaccination, in which the vaccine was administered subcutaneously to chicks at hatching. In ovo administration of the vaccine at day 17.5-18.5 of incubation significantly reduced the number of culled chicks, early mortality, and overall mortality during the grow-out period compared with conventional vaccination. However, hatchability was significantly lower in in ovo-treated chicks. Overall livability and feed efficiency were higher in the in ovo-treated chicks than in conventionally vaccinated chicks. Total field-caused condemnations and condemnations due to airsacculitis and septicemia/toxemia were also lower in the in ovo-vaccinated chicks. No difference in the leukosis (MD) condemnation rate was observed between the two treatment groups. In ovo vaccination provided 93.25% protection against challenge with a very virulent strain of MD virus (strain RB1/B); by comparison, the conventional vaccination method provided 89.58% protection.
评估了一种二价马立克氏病（MD）疫苗（火鸡疱疹病毒+SB-1株）在鸡胚内接种的田间安全性和有效性。使用Embrex公司的INOVOJECT自动蛋注射系统将疫苗接种到商业肉鸡种蛋中。与传统的疫苗接种方法进行了比较，传统方法是在雏鸡出壳时皮下接种疫苗。与传统疫苗接种相比，在孵化第17.5 - 18.5天进行鸡胚内疫苗接种显著减少了出栏期淘汰雏鸡数量、早期死亡率和总体死亡率。然而，鸡胚内处理的雏鸡孵化率显著较低。鸡胚内处理的雏鸡总体成活率和饲料效率高于传统接种疫苗的雏鸡。鸡胚内接种疫苗的雏鸡因田间原因导致的总废弃率以及因气囊炎和败血症/毒血症导致的废弃率也较低。两个处理组之间白血病（MD）废弃率没有差异。鸡胚内接种疫苗对超强毒力马立克氏病病毒（RB1/B株）攻击提供了93.25%的保护；相比之下，传统接种疫苗方法提供了89.58%的保护。
