Poultry immunity test serves as early warning system

A new immune system test could help poultry producers improve the resistance of their flocks to disease.

The new test warns poultry producers that flocks could experience secondary infections because of immune system suppression. Combining this with new immune-system boosting drugs would improve poultry welfare, and result in cheaper, better quality poultry products for consumers, say scientists involved with the Eureka E! 2692 Molecular Tests project.

The new EU-funded test provides poultry companies with an early warning for flocks that will experience secondary infections because of immunosuppression. It identifies molecular markers and can be performed in two days on blood samples from poultry, using equipment already available in diagnostic laboratories.

Current immune system tests are imprecise, expensive and take weeks - providing information too late to be useful, the scientists say.

Poultry is the fastest growing livestock industry worldwide, benefiting from production and price advantages as well as being viewed as healthy food. The relatively short turn around - five to eight weeks for broiler chickens -- means production involves intensive housing and management to maximise output.

Such crowded conditions leading to an increase in the incidence of disease and reduced immunity, a serious problem for commercial poultry producers worldwide. The major cause is viral infection.

All viruses can cause immunosuppression to varying degrees but Marek's disease, infectious bursal disease and chicken anaemia are particular concerns. A simple test to identify flocks that have been immunosuppressed by non-apparent infections was needed.

The new test is the outcome of research initiated at the University of Georgia and continued at the Institut Ruder Boskovic in Zagreb under the EU-funded Eureka projects.

"The test is ready but we need to develop the companion immunotherapeutic to convince an animal health company to take it on," said project leader Dr William Ragland of Zagreb Biotek in Croatia.

He had hoped that there would be direct commercial interest in the test alone but the animal health industry is conservative and companies are hesitant because they have lost considerable market in Asia due to the current outbreak of bird flu.

Immunosuppressive viral diseases are a great concern leading to mortality, reduced growth rates and productivity, poor response to vaccination, condemnations due to secondary infection, medication costs and downgrading at the processing stage.

Disease and disease control are estimated to cost the industry seven to ten per cent of turnover a year.

Increased use of antibiotics and chemicals to fight opportunistic secondary infections is also a major concern for human health. It is linked to the presence of residues in meat products, release of residues into the environment and increased antibiotic resistance.

Reduced flock immunity is a serious problem in the poultry sector. Early warning helps inform poultry companies as to expected profitability.