Biosecurity Top Tips

A thorough review of the whole range of biosecurity measures that need to be addressed to minimise the risk of diseases entering the pig herd by Amy Quinn and Michael McKeon of Moorepark. They presented their paper on the topic at the Teagasc Pig Farmers Conference in October 2013.
calendar icon 19 December 2013
clock icon 12 minute read

Good biosecurity is important for all pig units. Some pig farmers may feel that their unit already has all the diseases available to catch so therefore there is no need to worry about biosecurity.

This is a very dangerous approach as new variant strains, e.g. porcine reproductive and respiratory syndrome (PRRS), can circulate which can effectively cause a re-infection and performance break-down on your farm.

The list below highlights the key points that all units should adhere to irrespective of their current health status.


The introduction of stock - typically, replacement breeding stock - is the most common entry path of disease to units purchasing stock.

To reduce the risk of introducing diseases with incoming stock, the following general guidelines should be adopted:

  • The health status of the source herd should be identified when selecting the source and then supplied on a regular basis (e.g. quarterly) thereafter if keeping the same supplier. The health history of the source should also be considered when initially selecting the supplier. It is important to note that a recent health report is not a guarantee of the absence of disease merely that its presence was not detected on testing.

  • Keep the number of source herds to a minimum; ideally use a single source where possible with a stringent biosecurity programme.

  • Incoming animals should have been vaccinated prior to delivery (at least three weeks) in order for immunity to have developed and for the purchaser to revaccinate after arrival.

  • The isolation facility should ideally be located three miles but at least 400 metres from the rest of the herd. As a rule of thumb, the isolation facility should be far enough away so that it is not readily and easily accessible to staff as they perform their regular duties. Isolation facilities should also have its own unloading facility and located so that surface drainage and prevailing winds can not carry contamination to the existing herd.

  • All in-coming animals should be isolated from the herd for eight weeks, four weeks in complete isolation and four weeks with a sentinel animal (e.g. a cull sow). As the incubation period for different diseases varies, signs of illness may not be evident for several weeks, therefore, the length of isolation is crucial. The addition of a sentinel animal allows for the new stock to acclimatise to the diseases present on the unit. Pigs should be blood sampled at week four by your veterinarian and not removed from the isolation before results are received.

  • Preventive treatments such as de-worming and vaccination can be started in preparation for moving to the herd.

  • The isolation facility should be managed all-in/all-out. No animal should be moved from the isolation facility to the recipient herd until the most recent addition has completed the testing protocol and isolation period.

  • Animals should be carefully observed at least daily during the isolation period for signs of illness such as; coughing, sneezing, diarrhoea, blood or mucus in the urine of faeces, unusual or severe skin lesions and lameness. Pigs showing any signs of illness should be immediately separated and promptly examined by a veterinarian.

  • Duties should be sequenced so the person caring for the isolation animals does not come into contact with other pigs later that day. If possible, the person taking care of the isolation animals should have no other pig contact duties for that day, i.e. last job of the day.

  • Outerwear (boots, overalls, hats) worn while tending these animals should be only used in the isolation facility.

  • Equipment such as feeders, shovels, scrapers, hand tools, etc., used in the isolation facility should not be used in other parts of the pig unit.


Although diseases are most commonly introduced into a herd by movement of animals, there is also a perceived risk of introduction through staff on the unit.

To reduce the risk of introducing diseases through staff on the unit, the following general guidelines should be adopted:

  • Employees should clearly understand the biosecurity protocol for the unit.

  • Workers should have no contact with other pigs (including pet pigs) or pig manure outside of their employment and this should be a condition of employment.

  • Farm employees who have livestock other than pigs at their own home should be required to report to work personally clean and in clean clothes that have not been exposed to their own livestock.

  • Employees should be provided with outerwear and boots that are to be left on the farm when the employee returns home. Showering, changing and laundry facilities should be provided on the farm.

  • Prior to entering the canteen employees should remove workwear (boots and outer clothes) and wash hands.

  • The use of foot baths is an unreliable method of routine disinfection, unless boots are thoroughly scrubbed before immersion and adequate contact time in the disinfectant is permitted. Usually at least five-minutes contact time is required. Heavy duty work boots with deep corrugations in the sole are difficult or impossible to disinfect properly. Selection of work boots should take account of ease of cleaning.


There is a risk of disease introduction by people travelling between farms or between groups of animals.

To reduce the risk of introducing diseases with visitors to the unit, the following general guidelines should be adopted:

  • All visitors should sign a visitor declaration form or visitors book which should record the interval since their last pig contact, on arrival. Visitors should be aware of the biosecurity protocols for the unit prior to entry.

  • Visitors should not enter pens, passageways used for moving animals, or touch animals unless necessary.

  • Showering facilities should be provided for visitors to allow them to shower in and out of the unit using a clean/unclean area protocol.

  • Visitors should be asked to wear overalls provided by the unit or disposable overalls if none are available. Footwear should also be provided by the unit or disposable boot covers if none are available. If disposable gear is provided it should be disposed of on the unit.

  • Any sampling, measuring or recording equipment brought by visitors should have been thoroughly cleaned and disinfected. A stock of appropriate tools, extension leads and equipment should be kept on the farm to minimise use of tools and equipment, which have been used on other pig units.

  • Potentially contaminated hands and forearms should be washed with soap and water. Finger nails should be brushed clean.

Dead Pig Disposal

The collection of pigs by rendering trucks from units poses a biosecurity risk due to the collection of pigs from several units per day.

In order to reduce the risk of introducing diseases in this way the following general guidelines should be adopted:

  • Outline to staff a clearly defined routine for dealing with dead pigs and their removal.
  • Dispose of dead stock and after-birth promptly.
  • Provide safe sealed storage for dead pigs.
  • The rendering truck collection point should ideally be located off-site. Where this is not possible then meet the truck at the entrance to the unit.
  • Clean and disinfect all storage equipment after every batch.

Wild Boar and Hobby Pig Farmers

A biosecurity risk that is receiving heightened attention in recent years is the threat posed by wild boar and people keeping pigs as a hobby/pet. While it may seem like this is a minor issue, the numbers of both groups are steadily increasing. Since 2009, there have been 39 wild boar sightings mainly distributed in the midlands, eastern and south eastern regions of Ireland and in 2012, there were 941 registered herds with five pigs or fewer and a further 315 with 20 pigs or fewer.

Wild boar and hobby pigs threaten biosecurity as they have the potential to act as highly mobile disease reservoirs. They can carry a high number serious viral and bacterial diseases and parasites which pose a threat to commercial pig units.

In order to minimise this potential threat, it is recommended that the following instructions be followed:

  • Ensure the unit perimeter and buildings are secure to prevent entrance of unwanted animals.
  • If contact is made with these pigs the same procedure as if you had visited another pig unit (i.e. 24 hours pig free) should be followed.
  • If you know of any wild boar sightings in your area, ensure the sighting has been logged with the National Biodiversity Data Centre and the Department of Agriculture, Food and the Marine.
  • If you know of any hobby farmers or pet pigs in your area, inform the owners that a herd number is required for owning one or more pigs.


Vehicles pose a disease threat either from aerosol transmission if some pigs are on-board (alive/dead) or from the vehicles carrying infected organic matter. The documented risk is difficult to ascertain accurately in literature, however, the objective should be to minimise or completely eliminate the risk.

In order to reduce the risk of introducing diseases in this way the following general guidelines should be adopted:

  • Do not allow transport containing pigs into the unit, either with alive or dead pigs on-board.
  • Provide a ‘dirty area’ for transport which staff and pigs have no direct access to from inside the unit.
  • Ensure all feed bins and the pig lairage are accessible from the outside of the unit
  • Ensure pig trucks are washed, disinfected and dry before arrival.
  • Enforce the rule that unit staff do not enter the truck or step on the tailgate
  • Instigate a policy of 'no return' once a pig has gone beyond a certain boundary, i.e. pig has stepped onto the tailgate.
  • Provide all truck drivers with clean boots and overalls
  • Do not allow any truck driver to enter the pig unit.
  • Ensure all feed deliveries are full loads thereby eliminating the need for a truck to do two unit deliveries with a single load.


Most AI studs provide a low risk of disease outbreak but when it occurs, it can have rapid disease transmission across a wide area.

While the principle form of transmission is the presence of the pathogen (disease) within the AI dose, the physical delivery of the AI package to the unit can provide also a risk. Infection within the unit can also be transmitted from sow–to-sow if proper hygiene procedures are not adhered to i.e. sharing catheters.

In order to reduce the risk of introducing diseases in this way the following general guidelines should be adopted:

  • Get an AI stud heath report before deciding on which stud to purchase from.
  • Once selected get regular herd health monitor reports from the AI stud
  • Ensure the AI delivery box is ideally located away from the unit at another location or at a minimum secured on the outside of the unit.
  • Do not share catheters between sows to prevent bacterial cross-contamination.


The use of pig vaccines is an important tool to reduce the level of pathogens in the pig’s environment. The selection and type of vaccination (live or dead) is important to ensure that the risk of disease outbreak is reduced in a cost effect manner. In order to reduce the risk of introducing diseases in this way the following general guidelines should be adopted:

  • Select the most suitable vaccine for your unit based on: disease risk, mode of action (sow/ piglet), type (live /dead vaccine), cost, and benefit analysis.
  • Plan a suitable vaccination programme for your farm with the unit vet.
  • Ensure all vaccination of pigs is undertaken as a team to reduce individual fatigue. Two people vaccinating 400 pigs will lead to mistakes.
  • Ensure all vaccines are stored at the correct temperature, e.g. between 3°C and 50°C. Use a thermometer to verify the temperature. There should never be ice crystals in the vaccine bottle.

Rodents and Cats

Rodents and pests can both harbour and transmit disease. It is important to contain the level and ideally exclude them from the unit where possible. Rats and mice can transmit pig diseases such as leptospirosis, toxoplasmosis, erysipelas and swine dysentery. The common method of transmission is via urine, saliva, blood, faecal droppings or by contact.

As a rule of thumb a rat can eat 500g of feed per week but can contaminate 10 times the volume of feed eaten. While cats can reduce the mice/rat population, they can also spread disease themselves and, therefore, should be eliminated from units.

In order to reduce the risk of introducing diseases in this way the following general guidelines should be adopted:

  • Use a rodent bait plan
  • Routinely inspect building for evidence of rodent infestations and act immediately.
  • Instigate clear-areas around buildings to eliminate any vegetative or physical hiding places.
  • Ensure no cats are permanently present on the unit – do not feed them or encourage their presence.


In addition to bird infestations consuming significant amounts of pig feed - starlings eat 50 per cent of their bodyweight each day - they also pose a significant disease risk. Salmonella can spread through feed contact and bird droppings and other pig diseases can be physically transmitted from unit-to-unit over a wide area.

In order to reduce the risk of introducing diseases in this way the following general guidelines should be adopted:

  • Ensure all buildings, not just pig buildings, are bird-proofed.
  • Eliminate bird perch’s around the unit.
  • Promptly clean-up any feed spills around feed bins.
  • Reduce the bird population around the unit where necessary.

Pig Flow

All-in /all-out system should be used on units to reduce the exposure levels of pathogens in the pig’s environment. This reduces the risk of disease outbreaks where pathogens levels are high. It also prevents the transmission of disease from older pigs to younger pigs thereby improving the pig unit’s health status and growth rates.

In order to reduce the risk of introducing diseases in this way the following general guidelines should be adopted:

  • Ensure all rooms are emptied fully.
  • Remove all organic matter and wash rooms fully. Allow to dry and then disinfect and allow the room to re-dry before new pigs enter the room.
  • Never bring older pigs back from other pig housing even if they appear to be a similar size. They will transfer and increase pathogen levels, thereby increasing the risk of a disease breakdown within the house, e.g. meningitis.

Further Reading

Find out more information on the diseases mentioned by clicking here.

December 2013

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