In this first article in Tonisity’s two-part series on infection protection in pig herds, we discuss external infection from purchased animals, delivery of animals (including animals for export and carcasses) and people (including items brought into the barn). Infection protection covers several measures that can be carried out internally or externally, and the common purpose is to protect the herd from disease-causing infectious agents, bacteria and viruses.

It is important to protect your own herd, but also pig production in the geographical area where the herd is located. This not only has major economic consequences for the individual pig farm, but also major socio-economic consequences.

In this article, we share an overview of actions you can take on your farm to reduce the risk of disease in the herd. External infection protection aims to prevent the supply of infection from the outside and is extremely important to ensure the herd in the best possible way against losses due to diseases introduced into the herd.

Procurement of breeding animals and piglets

One should generally try to use the same supplier to maintain stable immunity in the herd and to the greatest extent possible, purchased breeding animals should be let in through quarantine rooms.

When purchasing breeding animals or piglets, you should ensure that animals with the same health standard as the standard of the buyer herd are purchased. The purchase of pigs with a lower health standard can provoke extensive outbreaks of disease in the buyer’s herd. Similarly, purchasing pigs with a higher health standard than the buyer’s herd can cause problems.  Disease outbreaks in the purchased pigs, due to infection from herd animals, can lead to propagation of the infectious agent and thus also cause disease outbreaks of those already in the herd.

Some infections such as meningitis (streptococcal infection), E. coli and Salmonella, the herd cannot be declared free of, either because it is not possible to investigate the pattern of infection or because the infection occurs in all herds.

Delivery of pigs

In connection with delivery, direct contact with the wagon and hauler must be avoided as much as possible. All dispensing facilities should always be kept clean and should at least be cleaned and disinfected before use.

One should be extremely careful when offloading slaughter animals, as a slaughterhouse trailer can carry all types of infection. The hauler can bring pigs on the trailer, but by demanding an empty and cleaned vehicle, you can ensure the best possible protection against infection.

The delivery procedure for a slaughterhouse trailer can be arranged in the following ways:

Directly from the barn (most risky method)

Direct delivery means that the animals go directly from the stable and via the ramp directly to the transport vehicle. It requires special care to ensure that the ramp and trolley are sufficiently cleaned to minimise the risk of infection.

It is important that the driver only stays on the truck and that the staff only stays in the barn and on the ramp. If pigs are running back, there is a risk of infection from the wagon.

Via delivery room/delivery fold

In the case of the delivery room/fold, a separate area is filled with the vacating pigs, after which the doors to the barn are closed. The hauler now can pick up the animals in the delivery area. The area is cleaned and disinfected after use from the outside as the last task of the working day. Clothes and boots used for this purpose must be washed before using them again in the barn.

A special type of dispensing room is a sluice. The idea of a sluice is that several batches of pigs can be delivered on the same load. The sluice is a room that has a door at both ends. The door to the barn is only open when animals are moved in from the stable area, after which the door to the barn is closed. The door to the ramp can then be opened and an employee in the sluice can move the animals out onto the ramp, where the driver moves the pigs into the trailer. When the room/sluice is empty, the door to the wagon is closed and the door to the barn opens again. The employee in the sluice goes the same way out as the animals and only enters the barn again after changing clothes and hand washing.

Via mobile delivery (safest delivery method)

In the case of mobile delivery, the animals are loaded onto a transport vehicle, which is driven to a reloading point as far away as possible (at least 50 meters) from the barn. The trolley is washed and disinfected immediately after use, as the last task of the working day. In general, the further the vehicle is away from the herd area, the lower the risk. However, at distances over 200 hundred metres, no additional safety is achieved. To be able to thoroughly clean both ramps and delivery trucks, it is important that all surfaces are smooth and whole, easy to clean and without gaps.

Personal access to the barn

• The anteroom must ensure that people do not carry infection into the herd area. By changing clothing and footwear, as well as washing hands (and showering), the herd area can be secured in the best possible way
• After visits to herds with lower health status, quarantine time must be maintained
• When people bring tools or medical equipment, it is important that there is also a procedure for how the gear is brought into the crew area. All materials must either be new or be able to be thoroughly cleaned and disinfected
• Pay special attention to mobile phones, they may be in small plastic bags or sanitised thoroughly before being taken into the herd area
• Visitors to the herd should always observe a minimum of 24 hours of quarantine after visiting another pig herd
• If visitors are professional and well-known to the farm, the quarantine requirement can be reduced to 12 hours from the previous herd is abandoned

When you need various materials in the herd, these can be let in through the anteroom. As much as possible, avoid utilising used equipment from other herds. New materials are unpacked at the transition between the unclean and clean zone. Used materials such as hand tools and mobile phones are washed and sanitised in the anteroom. It is recommended to have a separate mobile phone in the barn.

In part two, we will discuss external infection from:

• Pests (mice, rats, birds and another animals)
• Feed and bedding, from
• Airborne infection from neighbouring populations
• Semen