Turkey producers will be legally required to test for salmonella from January 2010. Olivia Cooper finds out what the new rules will mean to businesses

Turkey businesses are being urged to start preparing for new salmonella testing and monitoring rules set to come into force in 2010, as it becomes the next sector targeted by the EU Zoonoses Directive.

The chicken breeding and laying sectors have already seen the introduction of a mandatory testing regime, while 2009 will see a National Control Plan being rolled out in the broiler sector, extending to turkey producers in 2010.

Between October 2006 and September 2007 the EU carried out a survey to ascertain the level of salmonella infection in turkey flocks. It found that 13.6% of breeding flocks and 30.7% of fattening flocks tested positive for salmonella, with the incidence varying from nil to 82.9% across member states.

The UK fared reasonably well in the breeding sector, with just 4.4% of flocks testing positive. However, fattening flocks exceeded the EU average, at 32.2%. Despite this, the vast majority of positive tests were for strains not damaging to human health, stresses Jeremy Blackburn, executive officer at the British Poultry Council.

There were 112 reported incidents of salmonella in turkeys in Great Britain in 2007. The most commonly reported serotypes were S Derby and S Kottbus, which comprised 33% and 21.4% of total reports, respectively, and neither of which are a threat to human health.

Almost all year-round turkey producers are members of the Quality British Turkey Scheme, which requires them to have a salmonella eradication plan, says Mr Blackburn. Just three of the 317 QBT member farms were found to have salmonella present, none of which were strains threatening to human health.

“There is recognition that sometimes the smaller, seasonal producers need to look at their salmonella control. But 80% of turkey is sold under the QBT label. We are well ahead of many other member states.”

Human cases of salmonella have dropped sharply since the 1980s, with most infections caused by the strains S Enteriditis and Typhimurium. Levels of these serovars in EU turkey flocks were very low, being detected in 3.8% of EU fattening flocks and 1.7% of breeding flocks, against 4.6% and 0.5% in the UK, respectively.

The EU has, therefore, set a target rate of 1% presence of these two strains or lower, which it considers a realistic goal by 2012.

To achieve this goal, DEFRA has drawn up a draft National Control Plan, which from January 2010 will require all fattening flocks with more than 300 birds to test for salmonella three weeks before slaughter. Breeding flocks for rearing will have to be tested at day old, four weeks old, and two weeks before movement to a laying unit, with adult laying flocks of more than 50 birds tested every three weeks during lay and three weeks before slaughter.

Producers can carry out the sampling themselves, using mainly boot swabs and dust samples, and must send them to an approved laboratory. Animal Health will oversee the scheme and will randomly test 10% of holdings each year with more than 500 fattening turkeys or 250 breeding birds, plus all flocks which test positive for S Enteriditis or Typhimurium.

Full details of the NCP are yet to be confirmed and a turkey working group has been consulting with DEFRA to establish the most practical regime possible. It is possible that producers could be granted a derogation not to sample all flocks on the holding if they use an all in, all out system and have been free of Enteritidis and Typhimurium for at least a year.

Producers must keep records of when each flock is sampled for salmonella, the identity and age of the flock, the date of slaughter, the laboratory which undertook the analysis and the test results.

If a flock tests positive, arrangements may be made with the abattoir to reduce the possibility of cross contamination of other batches, by for example, arranging for slaughter to take place at the end of the day.

Should a flock test positive for Enteritidis or Typhimurium, producers must inform the Animal Health (State Veterinary Service). Disease control advice will be given and a notice may be served requiring the producer to clean and disinfect the infected building, which may then be re-tested to verify the serovar has been eliminated.

Tips on reducing Salmonella in turkeys

Salmonella does not usually cause health problems in turkeys, with only those under a week old likely to show any symptoms or mortality, says vet Stephen Lister, of Crowshall Veterinary Services, Norfolk.

Because turkeys have a longer lifespan than broilers, they tend to build up immunity and prevalence of different serotypes comes and goes from one year to the next.

Low levels of salmonella in breeding flocks mean that most transmission is via the environment, he adds. Good biosecurity and vermin control is, therefore, key to preventing infection.

“Decent terminal cleaning and disinfection is important.” Careful hygiene measures, including limiting visitors, wearing protective clothing, keeping footbaths outside houses, and effective cleaning, will all help to keep infection rates down.

Because of the difficulties of controlling the environment, free-range flocks, including organic, are more likely to be exposed to salmonella than flocks reared indoors. Seasonal producers with naturally ventilated sheds are also more at risk, as are those with multi-age sites.

“Wild birds will carry salmonella,” says Mr Lister. “Whereas it may be impossible to always prevent them entering a site or contaminating the range, they may be discouraged by avoiding standing water on the range, not feeding birds on range and cleaning up all feed spillages.”

Rats and mice are susceptible to salmonella and can even multiply the bug and make it more potent against poultry.

Feed and straw bedding can also be a source of infection, so they should be of the highest quality and stored in vermin proof areas prior to use, he adds.

Producers suffering particular problems could consider feeding competitive exclusion products to boost healthy gut flora, although the generally low levels of salmonella infection mean these are not widely used in the turkey industry. The same is true of vaccines, which are only available for S Enteriditis and Typhimurium serovars, and are therefore usually unecessary.

“The effort of the new sampling procedures, considering the role turkey plays in human food poisoning, is not a proportionate response,” says Mr Lister. “However, the more monitoring, the greater the chance of picking up on salmonella, so producers should take measures to reduce the chance of infection.”

Testing at a glance

  • All fattening flocks with more than 300 birds to test three weeks before slaughter
  • Breeding flocks for rearing will have to be tested at day old, four weeks old, and two weeks before movement to a laying unit
  • Adult laying flocks of more than 50 birds tested every three weeks during lay and three weeks before slaughter