Simultaneous vaccination of day-old chickens against Newcastle and Marek's diseases

Commercial day-old chicks vaccinated against Marek's disease (MD) with turkey herpesvirus (HVT) were tested for their ability to respond to a live Newcastle disease vaccine (NDV) - La Sota strain - administered by different routes. Simultaneous vaccination of day-old birds with HVT and NDV did not affect the immune response to NDV nor the viraemia induced by HVT vaccination. MD and ND vaccinations performed together, the first by the intramuscular route and the second by beak dipping, gave a valuable protection in flocks exposed to the two diseases.