How to detect and prevent heat stress in pigs on farm?

  • Subject
    Description of heat stress on farm in all pig categories, with the focus on lactating sows and finishing pigs
  • Target audience
    Competent Authorities, inspectors and welfare policy workers of the EU Member States
More info and sources
With increasing global temperatures, the risk of heat stress for farm animals is growing. EURCAW-Pigs published a review and webdossier, and inspection tools, to support welfare inspectors and other stakeholders in the field of climate control on pig farms.

The review describes heat stress in all pig categories, but with the focus on lactating sows and finishing pigs. The review is concluded with practical advices to prevent heat stress in pigs, beneficial for animal welfare, performance and working conditions.



As pigs are not able to sweat and in livestock houses they generally do not have the opportunity to wet themselves, an ambient temperature above the upper critical temperature leads to reduced welfare and performance. This upper critical temperature varies per pig category (including weight) and is considerably lower for lactating sows than for newborn piglets. At high humidity even lower temperatures can lead to heat stress.

Measures to prevent heat stress can preferably be combined with the weather forecast to prevent heat accumulation in pig buildings. The main measure is to regularly check indoor temperature and relative humidity and to use a table on corresponding temperature-humidity-index values to assess the heat burden of animals and to start with countermeasures before the threshold is reached.

Tools for welfare inspection

When visiting a pig facility it is necessary to have a toolbox of indicators to detect heat stress. There are many indicators available, both environmental (risk factors) and animal based, of which some show an acute, others a longer term effect (pen fouling) of heat stress. Individual indicators are not sufficient as a signal for heat stress, a combination of indicators is a better proof. The following indicators - described in indicator factsheets - are recommended as the most useful and proven indicators for heat stress:

The corresponding webdossier is based on the review, and also includes suggestions for national training (training guide) in EU Member States on the topic of heat stress in pigs.

Official inspectors and experts from member states are invited to contact EURCAW-Pigs with any suggestions, comments or questions to further improve the review.

Introphoto: Thermoregulation (©WUR)