New advice on reducing nicarbazin residue in British Chicken

By adopting new advice, poultry producers can further reduce the incidence and levels of nicarbazin residue in British chicken, as Richard Allison explains

The poultry industry has been actively working with the Food Standards Agency in identifying ways in which the sector can reduce the incidence and levels of nicarbazin residue in British chicken.

Nicarbazin is a feed additive used for the successful treatment of coccidiosis, a potentially fatal and debilitating disease for birds. However, testing of chicken livers as part of the National Surveillance Scheme occasionally finds traces of the additive.

The number of samples testing positive for nicarbazin has fallen substantially since 1998, from 25.5% in 1998 to 5.8% in 2007.

However, while this reduction is welcome and levels are not a significant food safety risk to consumers, Gillian Asbury of the primary production division of the Food Standards Agency said the FSA wanted to reduce levels further.

“We want to see levels as low as possible and in particular, we would like to see a fall in numbers of samples testing 100ug/kg or more.”

National Surveillance Scheme samples testing over 200ug/kg are reported as positives while whose with a level over 1000ug/kg will trigger an on-farm investigation by the Animal Medicines Inspectorate.

Parallel to this, as British Poultry Council executive officer Jeremy Blackburn explains, the poultry industry accepts that consumers require assurances that British chicken contains the lowest possible residues of feed additives. And there is a fear that if the industry does nothing, it risks losing nicarbazin in the longer term.

So this prompted a joint industry/government project, with the aim of identifying the causes of the contamination through a questionnaire of poultry producers. A high response rate of 86% meant the project could gain an accurate picture of practices on farms that both tested positive and negative.

The key finding is that there were several likely causes, all relating to feed storage and handling, says Ms Asbury. “The higher residue levels of over 1000ug/kg were maybe due to a breakdown in bin management systems.

“One area of bin management that could be improved is an awareness of the amount of medicated feed required.”

The study highlighted that although it is best practice to empty bulk bins between feed deliveries, it does not always happen in practice, probably because managers are reluctant to risk running out of feed.

Therefore, producers are over ordering feed containing nicarbazin, which then complicates bin management.

This is supported by responses to the questionnaire suggesting that some farm managers are unaware of precisely how much feed containing nicarbazin is needed on-farm.

“We, therefore, recommend producers only order the amount needed and avoid ordering excess feed containing nicarbazin,” she says.

A key development which is set to help producers check whether their systems are working is the launch of a new on-farm test next year by Elanco.

As the company’s senior veterinary adviser Barrie Fleming explains, the new device is “a bit like a pregnancy test. A sample of feed can be taken, for example, from a feed bin. The feed is then prepared and tested for the presence of nicarbazin.

“We envisage producers using the device to check that the change from nicarbazin containing feed to non-nicarbazin containing feed has been properly implemented.

“If it shows positive, then the bin needs to be completely emptied before the next delivery of feed. If it shows negative, then it demonstrates that the feed change over has probably been managed correctly with a resultant low risk of a residue in the chickens.”

In essence, the device can be used to measure or confirm the effectiveness of bin management when changing feed from nicarbazin containing to non-nicarbazin containing feed, he said.

The project group aims to send producers an e-leaflet early next year giving advice on reducing nicarbazin levels including all recommendations from the initiative, which FSA hopes will be adopted across the industry. Meanwhile, for more information visit

Top tips

  • Continue following current best practice
  • Be aware of the precise amount of nicarbazin feed needed for the birds and which feeds contain it
  • Devise a system to ensure any bin containing nicarbazin feed is completely emptied prior to the five-day pre-slaughter withdrawal period
  • Regularly test feed using the Elanco on-farm feed test
  • Managers should remove any existing blame culture
  • All levels of farm staff should be trained in the use of nicarbazin-containing feed