Why is my chicken so irritable?

Dr Olivier Sparagano, of the school of agriculture, and his team have examined ways of eradicating poultry red mite from egg-producing flocks and hope eventually to develop a vaccine.

Researchers working on a food and rural development programme learned from farmers that the red mite was a major problem, cutting egg production at some units by up to 10pc.

The team secured grant funding to survey farms across the North of England and Scotland to gauge the level of infestation and what producers were doing to control the pest. The project was named "Why is My Chicken So Irritable?"

"More than 80pc of the farmers we visited said they had a red mite problem," said Dr Sparagano. "The move to free range from cages could make the problem much worse, as it is more difficult to find the mites in the open."

The way ahead seemed to lie in finding a vaccine to boost the chicken's immunity.

Sam Arkle, a student involved in the project, said the team hoped to identify a protein which could form the basis of the vaccine and which would raise the level of antibodies in the bird.

"The red mite feeds on the chicken's blood and causes the bird to suffer from anaemia, which affects the quality of the egg," he said. "If we could find a vaccine that would stop the mite from being able to digest the blood, it would fail to survive. The key lies in finding the right protein.