Archived News

Newcastle Disease and Poultry

June 13, 2016

By Justin Cox

Newcastle disease is a leading killer of chickens in the developing world. An innovative genomic approach led by UC Davis could enhance human nutrition, food security and livelihoods in Africa, and around the world.

Small-scale poultry production has the potential to dramatically alleviate malnutrition and poverty in Africa’s climate-stressed rural communities, but a massive barrier called Newcastle disease is standing in the way of making it sustainable. Newcastle disease is caused by a deadly and highly contagious virus; when one chicken falls sick, the rest of its flock is likely to follow. Newcastle disease causes mortality in as much as 8 percent of an infected flock, with devastating economic consequences for farmers who depend upon poultry.

Breeding a chicken resistant to Newcastle

A transdisciplinary program at UC Davis has set out to breed a chicken with increased resistance to the disease. The idea is that genetic improvement, as an alternative to just vaccines, could alleviate malnutrition in the developing world. It is a holistic approach to a very complex problem.  

Poultry represents a great opportunity to increase food security because, unlike cattle or other large livestock, chickens can be raised on small plots of land and require fewer resources. They’re also nutritious and provide not only meat, but also a steady supply of eggs. Their convenience is offset, however, by challenges posed by Newcastle disease, as well as stress induced by the high temperatures common in many less developed countries.

”Recent advances in genetic and genomic technologies allow us to address the most challenging traits in poultry production, which are disease resistance and heat tolerance,” said Huaijun Zhou, director of the Feed the Future Innovation Lab for Genomics to Improve Poultry and Chancellor’s Fellow in the UC Davis College of Agricultural and Environmental Sciences. Zhou added: “This promising approach not only naturally enhances resistance to Newcastle disease, but also improves vaccine effectiveness.”

The work supports U.S Agency for International Development’s (USAID) agricultural research and capacity building work under Feed the Future, the U.S. Government’s global hunger and food security initiative.

A One Health approach to prevent Newcastle disease

The research program is an embodiment of the One Health approach, which holds that the health and well-being of animals, people and their shared environment are inextricably linked. The work is a collaboration between the UC Davis College of Agricultural and Environmental Sciences, the UC Davis School of Veterinary Medicine and the One Health Institute, along with Iowa State University, University of Ghana, Sokoine University of Agriculture in Tanzania and University of Delaware. Bringing together diverse expertise allows the problem to be viewed through many professional lenses, allowing for solutions that go beyond the sum of their individual parts.

“Breeding a chicken that is resistant to Newcastle disease could have a tremendous impact on the health and food security of people across Africa,” said David Bunn, an advisory committee member to the USAID-funded program and former project manager with the One Health Institute. “This program is an example of how UC Davis and USAID are tackling complex problems throughout the world.”

More reliable poultry production promises higher incomes and better nutrition for African women and children, many of whom typically raise chickens as a means to generate income and provide food for their families. The result would be increased food security, improved nutrition and better livelihoods on the continent.

An inexpensive and effective Newcastle vaccine is currently available to protect chickens against the disease, but unfortunately routine vaccination of chickens in Africa has been difficult to implement and maintain.

Vaccination efforts have been very challenging for a number of reasons, including poor agricultural services, a lack of cold storage to keep the vaccine cool during transport and unreliable distribution. There have also been incidents in which the product delivered did not actually contain the vaccine, which has led to a lack of trust on the part of poultry producers. 

“This program is complimentary to vaccination,” said Dr. Rodrigo Gallardo, Co-Prinipal Investigator on the program and Assistant Professor of Poultry Medicine at the UC Davis School of Veterinary Medicine. “Our goal is to help vaccines do their job by generating a more resistant indigenous chicken that responds better to vaccination and challenges in the field”.    

Using genomics to fight Newcastle disease 

The UC Davis program could provide a promising alternative to vaccines by producing a breed of chicken that is more resistant to Newcastle disease in the first place.

Zhou, Bunn, Gallardo and their collaborators are applying innovative genomic approaches to identify genes or genetic markers associated with resistance to Newcastle disease and heat stress in chickens but applying that knowledge using traditional breeding methods. The chickens that show these resistant genetic variations will continue to be selected for breeding with one another until they have a more resistant strain of the chicken.

The team is working with geographically indigenous poultry breeds on both coasts of Africa at the University of Ghana and the Sokoine University of Agriculture in Tanzania, as well as experimental populations in the U.S. The project is happening in multiple parts of Africa so that local strains are bred and can be made available.

"The development of an improved breed with greater resistance to Newcastle disease is a novel approach to this devastating problem, and it holds great potential,” said Dr. Terra Kelly, program manager for the project. “We hope to expand this work in the future to address other important diseases of poultry in other parts of the world.”

Next steps to eliminating Newcastle disease

The research teams in the U.S. and Africa are working to identify the best system to effectively place the improved chicken breeds into the hands of farmers and communities, while providing the knowledge and tools necessary to support continued genetic improvement.

The research program aims to serve as a scalable model that can be replicated on other continents and address other important poultry diseases, alleviating hunger and improving lives.

 



 Justin Cox - jcox@ucdavis.edu / 530-219-5227