Feather insights could curb spread of poultry virus | The Roslin Institute
New research published in Avian Pathology highlights a critical gap in how the poultry industry manages Marek’s disease, a highly contagious viral infection capable of triggering cancer-like tumours. While current strategies successfully reduce illness and mortality in individual birds, the study suggests that shifting focus toward flock-level transmission could be the key to better disease control.
The Limitations of Current Protection
Scientists found that both vaccination and genetic resistance are effective at protecting individual hens from the most severe symptoms of the disease. However, when it comes to the spread of the virus within a flock, these two methods perform very differently.
The study revealed that only vaccination significantly reduces the amount of virus shed into the environment via feather dust. In contrast, hens bred specifically for genetic resistance to the disease showed no reduction in virus shedding and provided no protective effect for their susceptible flock mates.
Future Directions in Breeding and Vaccination
The research team, which included collaborators from the US National Poultry Research centre, the Swedish University of Agricultural Sciences, and INRAE in France, suggests that current breeding programmes often overlook traits linked to reduced virus spread. Incorporating feather viral load as a metric could change this.
By selecting birds with lower feather viral loads, producers could potentially reduce the total amount of virus circulating in poultry environments. This approach may not only improve overall flock survival but could also slow down the evolution of the virus itself, providing a more sustainable path forward for disease management.
Frequently Asked Questions
Why is vaccination more effective than genetic resistance at stopping the spread of Marek’s disease?
While both methods protect individual birds from illness and death, the study found that only vaccination significantly reduces the amount of virus shed into the environment through feather dust, thereby limiting the exposure of other birds in the flock.
How can feather samples help manage the virus?
Because the virus is shed through feather follicles, feather samples provide a non-invasive way to measure viral load. This data can be used to guide breeding programmes and inform the development of more effective vaccines.
What are the consequences of ignoring virus shedding in breeding programmes?
Current breeding programmes often focus exclusively on survival and tumour resistance. By failing to account for how much virus an individual bird releases, these programmes may allow the virus to continue circulating and evolving within poultry environments.
How might the integration of flock-level metrics change the way the poultry industry approaches infectious disease control in the coming years?