Field safety and efficacy of in ovo administration of HVT + SB-1 bivalent Marek's disease vaccine in commercial broilers.

Abstract

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.

• Authors: G Sarma, W Greer, R P Gildersleeve, D L Murray, A M Miles
• Journal: Avian diseases (Avian Dis) 1995 Apr-Jun Vol. 39 Issue 2 Pg. 211-7 ISSN: 0005-2086 [Print] United States
• PMID: 7677641 (Publication Type: Clinical Trial, Journal Article)

Chemical References

• Viral Vaccines

Topics

• Animals
• Body Weight
• Chick Embryo
• Chickens (growth & development)
• Drug Administration Schedule
• Energy Metabolism
• Marek Disease (prevention & control)
• Safety
• Vaccination (methods, veterinary)
• Viral Vaccines (administration & dosage, adverse effects)