The UK poultry sector has in recent years successfully cut the incidence of nicarbazin in chicken livers, but routine surveillance by the Veterinary Medicines Directorate continues to find a small number of samples with detectable levels of nicarbazin.

While it is not a food safety issue with no risk to human health, both the Food Standards Agency and poultry sector are keen to eliminate it totally.

Peter Bradnock of the British Poultry Council explains that while feed bin management is key "we didn't really know if that is the only cause. Is it also some other cross-contamination of feed, or the result of feed withdrawal prior to catching encouraging birds to pick at litter which could contain treated feed from an earlier spillage?"

However, the fear is that failure to act could eventually lead to the withdrawal of nicarbazin (Maxiban), which is a very important coccidiostat for the UK where, it is used extensively in starter and grower diets. Maxiban is the only UK licensed product containing nicarbazin.

So what is the industry doing?

The FSA is working with the British Poultry Council, NFU, Veterinary Medicines Directive and Elanco Animal Health in a project, aimed at finding the cause and ultimately, drawing up a series of practical recommendations for producers.

The group appointed an independent project co-ordinator, Maire Burnett, who collated information from 275 farms producing the tested birds. Data included feed management aswell as other factors when the birds sampled were being reared.

As Mr Bradnock explains: "Previously, we just had farm data for the few occasional positive tests that exceeded 1000ppb, exceeding this level automatically triggers a State Vet Service [now Animal Health] investigation. But now we also have data relating to those with any detectable level, well below the action level, as well as all farms for which the sample showed no presence of nicarbazin, giving a much bigger data set and allowing statistical comparison."

A joint government-industry project is seeking the cause of low level nicarbazin residues in chicken livers. Jeremy Hunt takes a look at its latest findings

Charles Bourns of the NFU highlights that "one of the problems the study has overcome has been the time-lapse between detecting nicarbazin in the sample taken in the slaughterhouse and finding out precisely what conditions prevailed at the point of production."

Parallel to the study, Elanco Animal Health has been running training sessions with producers on nicarbazin use.

What were the results of the survey?

Starting last February, 320 chicken liver samples were collected from slaughterhouses over 12 months and tested. Results show a continuing reduction in positive tests for nicarbazin - 6.3% last year, down from the previous year's figure of 9.6%.

Based on the information, the project has come up with a series of recommendations (see panel), which reinforces the importance of careful feed bin management.

How can producers help reduce the risk of nicarbazin residues?

It's important that either a member of staff is present or that feed delivery drivers are given very clear instructions and bins are clearly labelled to ensure that feed is delivered to the correct bin and any errors must be rectified immediately.

All birds must undergo the full five-day withdrawal period prior to slaughter after receiving feed treated with nicarbazin.

Producers must always adopt a strict approach to feed bin management no matter how many bins are in use on the unit. It is essential that any bin that has received feed containing nicarbazin be completely emptied at least once in the period prior to five days before slaughter. Managers should keep detailed records and dates of when bins are emptied.

And it's important to remember that the feed can hang-up in bins and become the last feed to be taken out. Wherever possible, the project advises visually inspecting the entire bin to confirm all the contents have been removed.

Although management of a double bin system is much simpler than when single bins are used, a disciplined approach is still essential. Only one feed with one coccidiostat product should ever be put into a bin at the end of the starter period any bins that have contained starter feed must be fully emptied before feed with a coccidiostat is introduced.

Other factors also require vigilance such as clearing up any spillages of treated feed (and not simply covering with litter) inside the shed. Any treated feed could be picked up by birds in the latter stages when feed is withdrawn prior to catching.

The full results are to be published later this year.

Recommendations from the nicarbazin reduction project:

• Follow current best practice, as it has successfully cut nicarbazin residues.
• Ensure all levels of farm staff are trained.
• Managers should remove any existing blame culture to encourage mistakes to be identified and rectified quickly.
• Farm managers are aware of the precise amount of nicarbazin feed needed for the birds on the farm and which feeds contain it.
• Producers devise a system for both double and single bins, to make sure that any bin containing nicarbazin feed is completely emptied prior to the five day withdrawal period before slaughter.
• Feed being fed is tested regularly using the Elanco on-farm feed test (soon to be available). This will confirm the robustness of the systems used and protect against residues in poultry.

The Food Standards Agency, NFU and BPC are holding a press and farmer briefing on Tuesday 13 May (1.15pm on) at the British Pig and Poultry Fair, in the exhibitors seminar room next to the workshop area.