Guidance

Salmonella: get your egg-laying hens tested

How to take samples for testing, when you don't have to get a flock tested and what happens if one of your flocks tests positive.

You must take samples, eg faeces, from each of your flocks and send them to a laboratory for testing if you produce eggs on a commercial basis. This is part of the national control programme (NCP) for salmonella, which aims to control salmonella in poultry flocks across the EU.

A flock is a group of birds that shares the same air space, eg a chicken house or range area.

If you’re not sure if your birds are considered to be in one or more flock, you can ask for advice from the Animal and Plant Health Agency (APHA) in England, Scotland or Wales, or the Department of Agriculture and Rural Development (DARD) in Northern Ireland.

You’ll be prosecuted or fined if you don’t get your egg-laying hens tested as described in this guide. A fine can range from £100 to £4,500.

When you don’t have to test a flock

You don’t have to test a flock if you either:

  • only produce eggs for private use (not for sale)
  • have fewer than 350 hens and only sell eggs directly to consumers through farm gate sales, or supply local shops (eg village shops) that only sell to consumers

Register your flocks before you get them tested

You must register each premises where you keep your flocks on one of the following:

When you must not sample

Avoid taking samples from chicks, pullets or hens during or shortly after giving antibiotics that affect salmonella. APHA or DARD could declare your flock positive for salmonella if:

  • inspectors see from the flock medicine book that you have given antibiotics
  • the laboratory tests find antibiotics in samples taken by inspectors

Get advice from your vet about antibiotics

You should speak to the vet who prescribed the antibiotics in one of the following, depending on where you farm:

  • APHA if you farm in England, Scotland or Wales
  • DARD if you farm in Northern Ireland - you can ask them when to test after giving antibiotics

Paying for samples and tests

You’ll have to pay for both of the following regular operator samples and tests, as well as the routine official control samples.

Find out what you’ll have to pay for tests and samples.

Take samples from your flock

You’ll have to take different kinds of samples in different ways depending on your situation.

Take samples from chicks

When chicks are delivered to you, you must send the following for laboratory testing:

  • one hatchery tray liner or one delivery box liner for every 500 chicks, up to 10 for each delivery
  • any chicks that are dead when they arrive from the hatchery, up to 60 carcasses

Take samples from pullets

You must take samples from pullets (young hens, also called rearing hens) 2 weeks before you place them in the layer unit or house.

Take samples from adult egg-laying hens

You must take samples from adult egg-laying hens in the layer unit or house:

  • when they’re between 22 and 26 weeks old
  • every 15 weeks after that

How to take samples from barn or free-range flocks

You must use boot swabs (fabric overshoes) to collect samples from barn or free-range hens.

You can buy sampling equipment from the government-approved laboratory you plan to send samples to, or from your vet. You can also ask your nearest APHA office or DARD for advice on where to buy sampling equipment.

You should use:

  • disposable plastic overboots
  • 2 pairs of boot swabs
  • tap water or bottled still water for moistening boot swabs - never use sparkling water or water treated on the farm with antibacterial agents or acids
  • disposable plastic gloves
  • sealable bags or sample pots
  • packaging for sending your sample bags or pots to the laboratory

Prepare to take samples

Take samples in the existing bedding - don’t put new bedding down.

Gather all the equipment you’ll need before you go into the laying house, to prevent contamination before, during and after sampling. You should take special care to avoid contamination if you keep other animals (especially pigs or cattle) on your premises.

To prevent disinfectant or sanitiser affecting your sample, you:

  • shouldn’t use hand sanitiser on your plastic gloves
  • should put on your plastic overboots after you’ve walked through disinfectant

If you do wear plastic overboots when you walk through disinfectant, you should put on a another pair afterwards to protect the boot swabs from the disinfectant.

Take samples from the flock house

You should sample only the inside of the house, even if you’re sampling free-range birds that spend part of the day outside. Also, avoid sampling the areas just inside doors and pop holes, as they may have been contaminated by material from outdoors.

Take 2 pairs of boot swabs from each flock. Moisten the boot swabs with water before you take samples - the water you use must be sterile and not contain any antibiotics (antimicrobials) or sanitisers.

Divide the house into 2 equal parts for sampling, and use one pair of boot swabs in each part. Take at least 100 steps with each pair of boot swabs, walking round the entire house. Drag your feet on the floor to pick up as much material as possible. If the house is divided into several pens, spend more time in the larger pens and less in the smaller pens.

When you’ve finished sampling, take the boot swabs off and turn them inside out carefully so that the material you’ve collected stays on them. Put the boot swabs in a sample pot or sealable bag to send to the laboratory.

How to take samples from caged birds

You must collect faeces samples from caged birds. You should gather all the equipment you’re going to need before you go into the laying house, to prevent contamination before, during and after sampling.

Run the droppings from end of belts, scrapers or pit on the day of sampling so that you collect fresh material

You can buy sampling equipment from the government-approved laboratory you plan to send samples to, or from your vet. You can also ask your nearest APHA office or DARD for advice on where to buy sampling equipment.

You should use:

  • 3 large fabric swabs for cage houses with belts (that catch the droppings) that don’t have scrapers (for scraping faeces off)
  • disposable plastic gloves
  • sealable bags or sample pots for faeces
  • packaging for sending your sample bags or pots to the laboratory

Prepare to take samples

You should gather all the equipment you’re going to need before you go into the laying house, to prevent contamination before, during and after sampling.

Run the droppings belts or scrapers on the day of sampling so that you collect fresh material.

Take samples from belts or scrapers

You should collect pooled faeces from places such as the scrapers at the discharge ends of each of the droppings belts. Use any of the following:

  • your gloved hands
  • inverted bags
  • spatulas

Collect faeces from the belts or scrapers on every row and tier of the cages so the samples are representative.

If there isn’t a scraper on the end of the belt that gathers faeces, use a large fabric swab and rub this over the discharge ends of the belts after you’ve run them to collect fresh faeces. This exposes new areas of belting at the discharge end so that you can take more representative faeces samples.

You must collect one sample from pullets and 2 samples from adult birds. Each sample must weigh 150g. Place the samples in a pot or sealable bag to send to the laboratory. If each sample weighs less than 150g, the laboratory won’t carry out the testing and you’ll have to send more samples.

Label samples

On each label you must include:

  • the date you took the sample
  • your registration number or your County Parish Holding (CPH) number or DARD flock number
  • the identification of the flock - house name or number and the month and year you moved the flock into that house for multi age flocks, use the date when you moved the oldest birds
  • the name and address of the flock’s holding
  • the age of the birds in the flock
  • the number of birds in the flock
  • the contact details of the person sending the sample

In Northern Ireland there may be different requirements please contact your local DARD office.

Send samples to a laboratory

You should send your samples on the day you collect them.

Refrigerate your samples at 4°C if you can’t send your samples on that same day. Make sure the testing laboratory receives your samples within 4 days of when you collected them, otherwise you’ll have to take new samples.

You must send your salmonella NCP samples to a UK approved laboratory. Find laboratories approved by:

The laboratory usually sends the results to the person who sent the sample and the person the sampled flock is registered to. If the sample tests positive for salmonella, the laboratory will also send the results to Defra.

Official sampling at your premises

In Northern Ireland, officials from DARD take samples. In England, Scotland and Wales, an APHA official, authorised vet or Industry Classification Benchmark (ICB) auditor (if your flock is in the Lion Code scheme) take samples.

They will take samples once a year if you keep more than 1,000 birds on your premises.

Officials from APHA or DARD may also take samples in other situations:

  • one of your flocks gets a positive result for salmonella
  • they’re investigating a food-borne outbreak that might be linked to a specific poultry farm and suspect a salmonella infection on your holding

You won’t have to pay for an official control sample in these cases.

What happens if you get a positive test result

From a laying flock

Both of the following will happen if a sample from any of your laying flocks tests positive for Salmonella Enteritidis or Salmonella Typhimurium (including monophasic Salmonella Typhimurium) that isn’t a result of vaccination:

  • APHA officials will visit your holding and take an official sample to confirm the positive result
  • you’ll have to keep the eggs on your premises while you’re waiting for the test result

You won’t be allowed sell your eggs as Class A if the official sample confirms the positive result or you run out of storage space while waiting for the result. You’ll have to do one of the following instead:

You must mark eggs in one of the following 2 ways if you have to sell them as Class B:

  • with the official Class B mark (a circle with the letter B inside)
  • use a spray or food dye to leave a coloured mark

Egg marketing inspectors will visit your premises to check you’re complying with the restrictions.

Extra samples

When APHA officials visit to take the samples, they may take 5 bird carcasses and store the organs. If the samples give a negative result, APHA officials may have the stored organs tested for residues of antibiotics. If any residues are found, the test result may be treated as positive for salmonella.

APHA officials will also take official control samples from every other flock on your premises.

They will visit again when a new flock is placed in a house in which the last flock had a positive test result. They will take this official control sample when the birds are between 22 and 26 weeks old.

You won’t have to pay for official control samples taken in response to a positive result.

A government vet will also visit your holding to give advice on salmonella control. In Northern Ireland contact DARD or your private vet for advice.

From a rearing flock

If a sample from your rearing flock tests positive for Salmonella Enteritidis or Salmonella Typhimurium (including monophasic Salmonella Typhimurium), officials may visit your farm to confirm the result and offer advice.

Get advice on controlling infections for other types of salmonella

Get advice on how to control the infection from one of the following if your flock tests positive for other types of salmonella:

If your samples test positive for salmonella

You can ask for more tests, at your own cost if you think a positive test result is false. You must contact either of the following to get these tests or more information about retesting:

APHA or DARD will arrange for an officer to supervise the collection of any one of the following samples for testing:

  • 300 hen carcasses
  • 4,000 eggs
  • 2 dust samples and 5 boot swab samples from barn and free-range birds
  • 2 dust samples and 5 pooled faeces samples from caged birds

You can only get restrictions lifted and sell eggs from the flock as Class A eggs if the samples test negative.

Keep records

You must keep all your records for at least 2 years. APHA or DARD officials may check them at any time, eg during a routine NCP visit or after a positive test result.

In Northern Ireland there may be different requirements please contact your local DARD office.

Keep test records

You must record all of the following each time you take samples:

  • date and time you took the sample
  • identification of the flock sampled - the house name or number and the month and year the flock moved into the house
  • type of sample, eg boot swab or pooled faeces
  • age of the flock sampled - there may be more than one age if the sample is from a multi-age house
  • laboratory that tested the sample
  • test result

In Northern Ireland there may be different requirements please contact your local DARD office.

Keep movement records

You need to record any movement of birds to or from your holding. For each movement record the:

  • date of movement
  • number of birds
  • age of the birds
  • identification of the flock if you’re moving an entire flock - but only if you keep more than one flock on your holding
  • identity of the building or group of buildings into or from which you’re moving the birds
  • address that the birds moved from (including the building name or number)
  • address that the birds moved to (including the building name or number)

Food chain information documents

You must declare the flock’s most recent salmonella test result in the food chain information (FCI) documents that you send with the birds to slaughter if you market any meat from your birds as fresh meat.

You don’t have to declare the most recent salmonella test if you heat treat all the meat from the flock before marketing it for human consumption.

Declare salmonella test results

You must declare all the NCP Salmonella test results, negative or positive, as well as the date the sample was taken from the flock in the Food Chain Information (FCI) documents accompanying the batch to slaughter.

This is a legal requirement and the birds may not be slaughtered if this information is not provided.

Further information

Contact your nearest APHA office or DARD if you need more advice.

You can also read the code of practice for prevention of salmonella in laying flocks (PDF, 171KB, 51 pages) , which provides best practice for preventing salmonella.

Published 8 February 2016