Document type: report published by the European Reference Centre for Animal Welfare (EURCAW) Pigs
Authors: Bracke, M.B.M., Herskin, M.S., Marahrens, M., Gerritzen, M.A., Spoolder, H.A.M.
Summary: This report aims to support inspectors of EU member states in understanding the science related to pig welfare concerning thermal control and space allowance during transport of pigs, especially in relation to Council Regulation EC 1/2005 on the protection of animals during transport and related operations.
The concepts of thermal comfort and thermoneutral zone are described in relation to pig transport and relevant variables are discussed such as ventilation, humidity, body weight, breed, bedding, (lack of) food and water, transport duration, air quality and space allowance.
Council Regulation (EC) 1/2005 specifies that during long journeys of more than 8 hours the ambient temperature inside the vehicle should be maintained between 5 °C and 30 °C, for all animals, with a +/- 5 °C tolerance (Annex I, Chapter VI, Article 3.1).
In order to assess thermal comfort, inspectors should in particular take into account the ambient temperature (both outside and inside the vehicle) and relative humidity (RH) as environment-based indicators of pig welfare. Indicative thermal comfort zones of pigs related to body weight are: Pigs 10-30 kg: 14-32°C if RH< 80% and 14-29°C if RH> 80%; Pigs >30 kg: 10-25°C (30°C with mechanical ventilation and misting devices) (SCAHAW, 2002). For adult sows and boars (pigs >160 kg), no (validated) temperature ranges are available, but these animals appear to be more prone to heat stress than smaller pigs, and thus probably need much lower maximum temperature allowances (perhaps even as low as 15-20°C). As animal-based indicators of heat stress, inspectors should look for signs of panting (high-frequent, open-mouth breathing), pumping (heavy abdominal breathing), and dog-style sitting (hind quarters down, front part up). Animal-based indicators of cold stress include shivering and huddling. In extreme cases of thermal stress, animals may be exhausted/fatigued (unable to get up) or even dead on arrival (DOA).
Regarding space allowances, inspectors need to be aware that pigs have different space requirements depending on the behaviour performed (standing, lying, fighting, getting access to water) and ambient temperature: under elevated ambient temperatures they will need to lie laterally (on their side) without touching other pigs in order to cool down.
Council Regulation EC 1/2005 also specifies that all pigs must at least be able to lie down and stand up in their natural position, and the loading density for pigs of around 100 kg should not exceed 235 kg/m2 , while relatively more space (up to 20 % more) may be required depending on the breed, size, physical condition of the pigs, the meteorological conditions and the journey time (Annex I Chapter VII D).
In order to assess space allowance, inspectors should in particular calculate or estimate the m2/animal (based on the size/body weights of the animals), look at availaible free floor space (environment-based) and dog-style sitting. Overstocking is an important risk factor for overheating, so the heat-stress indicators mentioned earlier (panting, exhaustion, DOA) may also indicate overstocking.
The report also gives examples of good practices and ends with considerations regarding the implementation of Council Regulation EC 1/2005, in particular related to thermal comfort during hot weather and space allowances for weaners and sows. EURCAW tentatively suggests these persistent concerns may be solved by making better use of available data (e.g. temperature logs, journey duration, supply breaks and loading densities of vehicles recording axle weights) and/or by considering the use of additional surveillance systems such as cameras and other sensors inside the vehicle.
Article discussed in a news item on the EURCAW Pigs website
