Some 20% of poultry samples in a test in Ireland were found to contain nicarbazin, a drug banned from meat destined for human consumption, in 2004. Test data was collated and published by Teagasc's National Food Residue Database, which was created with funding from the Agriculture and Food Development Authority with the purpose of researching the chemical content of Irish produce.

Nicarbazin is an anticoccodal feed additive used to treat an infectious parasite that damages the gut of animals reared using intensive farming practises.

Food Safety Department researchers found evidence of this and similar drugs in one fifth of meat samples. The second most common drug found was lasalocid. Dr Michael O'Keeffe, head of laboratories in residual studies at the food safety department, told just-food: "We have found that there is a particular problem in relation to anticoccodal drugs in poultry production."

Farmers routinely treat young poultry with these feed additives in an attempt to pre-empt the spread of various infectious diseases. As the birds mature the drugs are supposed to be removed from feed to ensure that no residue is left in meat eaten by humans.

Another problem highlighted in the NFRD research is the presence of permitted drugs in meat samples. Farmer's are allowed to use various antibiotics to treat and prevent disease, but are supposed to set aside long periods of withdrawal before slaughter to stop them entering the human food chain.

"The department of agriculture and food has taken the situation quite seriously," O'Keeffe said. Often drugs entered the birds diet through feed mixing and cross contamination, he added. 

In 2004 the department began work with poultry producers to combat the problem, taking all those producers with a positive test result and individually examining how it might have occurred and how future contamination can be avoided. In addition, Teagasc plans to publish educational literature alerting farmers to the risks in the coming month.

The impact that the government's 2005 efforts have had remains to be seen. "Results for 2005 are not yet finalised," O'Keeffe said. "I can tell you that there still is a relatively high incidence of birds testing positive. It's an on-going problem and it's difficult to know whether any great advances have been made."