Salmonella: New rules for turkey farmers

New rules aimed at salmonella in turkey flocks have just come into force. Wendy Short quizzes Rob Davies of the Veterinary Laboratories Agency about the implications for breeders and producers

The new salmonella rules apply to all flocks of finishing turkeys, as well as to flocks with 250 or more breeding birds.

However, as Dr Davies points out, an exception has been made for turkeys reared for private domestic consumption, and birds from farms supplying small quantities of product direct to the consumer. Local retailers, who sell “primary” turkey products to the consumer, are also exempt from the rules.

The aim of the control programme is to reduce the number of turkey flocks that test positive for S Enteritidis and Typhimurium to a maximum of 1% by 31 December 2012. These two strains have historically been responsible for most outbreaks in cases of human infection since the 1980s.

However, DEFRA has acknowledged that voluntary industry control programmes in turkey breeding flocks have been successful. Therefore, day old turkey poults destined to be reared for meat should be free of S Enteritidis, and levels of S Typhimurium are expected to be very low, when they are placed on farms.

Within the EU, a national target has been set, with the aim of ensuring that fewer than 1% of breeding and fattening flocks test positive for the selected bacteria. From the end of 2010, further regulations will stipulate that batches of poultrymeat in which any type of salmonella is found (in a 25g monitoring sample) must not be offered on the market. This could result in the withdrawal of meat from sale.

Finishing turkeys

To test birds which fall into the relevant category, a minimum of two pairs of boot sock/swabs must be taken by the producer within the three week period before the birds are due for slaughter. The alternative is to use one pair of boot sock/swabs, coupled with a dust sample. Ideally, the producer should allow enough time for laboratory results to be returned, before the birds are moved to the slaughterhouse.

In cases where producers rear turkeys for finishing all year round and thin females aged 20 weeks or younger prior to total depopulation, the salmonella status of the flock must be determined before slaughtering the first birds. Information on flock status is likely to take about two weeks, following the first sampling, says Dr Davies.

In general, conventionally-reared turkeys are most likely to test positive for salmonella at between two and four weeks of age. On units where more than one batch of birds is being sent for slaughter, with an interval of more than six weeks between batches, a second sample may be required.

Breeding turkeys

Among breeding flocks, samples for salmonella detection should be taken from rearing flocks at day-old, at four weeks of age, and again two weeks before moving to the laying phase or the laying unit. In adult breeding flocks, samples will be needed at least every third week during the laying period. These samples can either be taken at the holding or at the hatchery.

For all flocks affected by the new rules, one official sampling is required on an annual basis. This has to be taken by an animal health officer, or other authorised person (see box). This official sample is permitted to replace the sample obtained by the producer.

Samples to be sent in for testing must be labelled using the identity of the flock, the number of birds it contains and the date when the sample was taken. Flock managers are also asked to duplicate this information for their own records, adding the age of the flock sampled, date of slaughter, the laboratory employed and the test results.

Suspect cases

An investigation will follow if there is a suspicion that a turkey flock is infected. On a finishing unit, it is recognised that in most cases, the suspected flock will have been slaughtered shortly after the results became available. However, producers will be served a notice, asking them to clean and disinfect the building used by the infected flock, and take further samples.

When the positive test occurs in the samples taken during the three weeks before slaughter, the abattoir must be informed, to allow for measures to be put in place to reduce possible cross-contamination.

In cases where S Enteritidis and Typhimurium are picked up, further tests will be carried out, to rule out any possibility of a positive result having been caused by a vaccine. The authorities acknowledge that vaccination against salmonella is not a common practice used on meat turkeys in the UK, although a S Typhimurium vaccine is sometimes administered to breeding flocks.

Managers of infected flocks will be given veterinary advice on how to deal with their birds. In some cases, vaccination may be recommended. There will be no charge applied to the cost of the investigation, nor for the expert advice.

Dr Davies recommends producer test deliveries of replacement birds for the targeted salmonella strain. Hatcheries and other suppliers should also be contacted, with a request for information on the bacterial status of their flocks.

Tips for avoiding salmonella infection

– To guard against contamination being passed between batches, disinfectants that are specifically designed to tackle salmonella should be used after cleaning. Sufficient time should be allowed for the house to dry out

– Separate boots and hand sanitiser should be used between houses. Provide clean boot dips for use when entering or leaving the site. Minimise the entry of people and vehicles on site

– Control rodents by effective baiting and use insecticides, to control litter beetles. Check regularly, to ensure that pest control is working

– Use straw from arable-only farms. Check bedding for rodent droppings

– Reduce access by wild birds and other wildlife

– Store feed delivery samples in containers and test dust inside feed bins for salmonella

– Enquire about the salmonella history of your feed mill.

Want to know more?

The national salmonella control programme has been introduced to comply with EU legislation. A full explanation of the new rules can be found on the DEFRA website (PDF).

Authorities managing the salmonella testing programme:

England: DEFRA

Northern Ireland: DARD

Wales: The Welsh Assembly

Scotland: The Scottish Government

Official controls

To monitor the new rules, the authorities will select from the following at random:

– All flocks on at least 10% of holdings with more than 500 fattening turkeys

– All flocks on at least 10% of holdings with at least 250 adult breeding turkeys between 30 and 45 weeks of age, including all holdings where S Enteritidis or Typhimurium has been detected during the previous 12 months

– All holdings with elite, great grandparents and grandparent breeding turkeys. This sampling may also take place at the hatchery

– Any time the authority considers it necessary