US research project investigates Blackhead disease
The US Poultry & Egg Association and US Poultry Foundation announced the completion of the funded research project – Blackhead disease (Histomoniasis): Reducing losses through molecular tracking and immunization – this week.
Carried out at the University of Georgia in Athens, USA, the project formed part of the Association’s comprehensive research program, encompassing all phases of poultry and egg production and processing.
Dr Robert Beckstead and Dr Larry McDougald, from the University of Georgia, found that there were many reservoirs of the disease and that "isolates of the causative agent vary widely in their virulence and drug sensitivity".
While an experimental live attenuated vaccine resulted in a delay in the onset of the disease, complete protection of the birds was never attained.
Studies on the transmission of the disease indicated that the spreading of litter in which flocks have had the disease may be an important risk factor in the spread of it, but the study concluded that more research was needed to identify insects or other mechanical carriers responsible for survival and spread of the Blackhead disease.
It added that the identification of strains with high virulence in chickens suggested that caution should be used when spreading litter from these farms, nearby other poultry operations.
