We often see that virus infections such as e.g. influenza and cytomegalovirus after weaning cause problems and give pigs a difficult start.

Several factors play a role:

  1. Support their immune system and stress them as little as possible!

When you wean pigs, remember that they are exposed to many big changes.

They switch environment, lose their mother, go from milk to feed and get new pen mates. Overall, this is a big stress load. Unfortunately, this load happens during a period when the passive immunity is heavily decreasing and where the active immunity does not yet protect.

The well-known pieces of advice should therefore be followed:

  • Insertion in dry and warm units
  • Frequent supply of feed of a good quality
  • Plenty of water supply, preferably with a constant water level

  1. Stop spreading of infection!

The most effective way of doing this is with strict sectioning.
You keep the infection going when pigs of different ages are mixed – also when it is only a few animals.

Always only move pigs forward. Read more about biosecurity in the form of McRebel:

Sectioning also means strict batch managment.

To achieve strict control of the number of farrowings – and thereby the number and age at weaning, several tools MUST be used:

  • Controlling young gilts’ heat and number per batch
  • Controlling how many returns to oestrus/sows that miss a service which ”are allowed” to be inseminated into the week batches
  • Use of insurance sows to remove the latest inseminated slaughter sows that are in excess in the batches.

Discuss it during the next veterinary visit if you see this as a challenge in your herd. 


Adjustment of ventilation when the outdoor temperature varies

The cold time of year is high season for respiratory disorders among both pigs and humans. Among the pigs the increase in symptoms is caused the varying temperatures day/night. To maintain good temperature in the stable, the ventilation goes down which often leads to heavy air in the unit (reduced air change) – this increases the infection pressure.


However, it does not have to be this way.

There are some things that can be done to ensure the freshest air possible for the pigs. The key words are minimum ventilation and heat.


Most ventilation systems have been set with a fixed minimum ventilation which is determined by the air necessary for survival and growth but without an impact on health.

Especially among the youngest animals in the nursery who do not produce much heat on their own but which need a lot of heat, we therefore experience that the ventilation switches to minimum for many hours a day especially during the night when it is cold outside and the activity level among the animals is low.

This leads to a worsening of air exchange and thereby also an increase of microorganisms, dust particles, ammonia and other things that can irritate the pigs’ nasal mucosa and increase the infection pressure in the unit.

If you want to ensure proper air quality with sufficient, fresh air, it is therefore necessary to increase minimum ventilation and the only right thing to do is actually to increase it until the air quality in the unit is good and you yourself feel that you can breathe in deeply and comfortably.


When the minimum ventilation is increased, there will be a risk that it gets too cold in the unit, and you therefore need to add extra heat.


In some systems, this happens automatically in connection with operations, but in others you must increase it yourself or buy heaters or heating cannons to maintain a reasonable temperature. The expense of such extra heating pays for itself many times in the form of better, healthier and stronger pigs that can use their energy on growing instead of fighting respiratory disorders.

Generally, pigs in a 2-climate system can handle a quite low room temperature without this affecting growth or feed consumption. If there is a good temperature in the animals’ living area, you can easily increase air exchange.


Measuring CO2

If in doubt whether the air quality in the nursery is good enough, it is possible for Ø-Vet to measure CO2 in the unit and in this way determine at what level the minimum ventilation should be.

It is not CO2 a such that we are interested in as the gas is not harmful in the concentrations present on a farm, but we use the concentration as an indicator of how good the air exchange is. The higher the CO2, the poorer the air exchange and therefore a bigger risk of accumulation of infectious agents and irritants.