
Knowledge
Dossier: Climate control and space allowance
This page provides background information and practical knowledge on the need for climate control and space allowance during transport of pigs. How do these affect pig welfare, and how can welfare problems be limited in practice?
This page describes the importance of thermal control during transport, and guidance for actions to take:
- Thermal comfort zone
- Cold weather
- Hot weather
Importance of space allowance during transport and related recommendations are described in terms of:
- Space and welfare
- Space requirements
- Deck heights
An educational video on good and better practices in pig transport was provided by the Animal Transport Guides project:
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Importance of thermal control during transport of pigs

Thermal comfort zone
Pigs are homeothermic animals, and thus heat production and heat loss should be balanced. Thermal comfort zones of pigs related to body weight are:
- Pigs of 10 - 30 kg: 14 - 32 °C if relative humidity (RH) is lower than 80% and 14 - 29 °C if RH is higher than 80%.
- Pigs of more than 30 kg: 10 - 25 °C.
- Adult pigs (>160kg): unknown, but the upper limit of the thermal comfort zone may be as low as 15-20 °C.
Read more & links
Ambient temperatures and ventilation:
- The legally required range of ambient temperatures (inside the vehicle) is 5 to 30 °C for long journeys.
- Ventilation systems are either free or forced systems. Free ventilation systems are common in vehicles used for short (less than 8 hours) journeys, whereas forced systems are a requirement for long-journey vehicles.
- The minimum air flow rate of fans should not be lower than 60m³/h per 100 kg live weight for long journeys.
Relevant links
- Transport guide extreme temperatures – Pigs, factsheet. EU Platform Animal Welfare, 2019
- Pig travelling, factsheet Animal Transport Guides Project, European Commission, 2018
- Guide to good practices for the transport of pigs, Animal Transport Guides project, 2017
- Council Regulation (EC) No 1/2005 on the protection of animals during transport and related operations, EC, 2004
- The welfare of animals during transport (details for horses, pigs, sheep and cattle), Scientific Committee on Animal Health and Animal Welfare, 2002

Cold weather
A good body condition is required to act as both an insulator and an additional energy reserve for creating body heat in cold temperatures.
In cold weather, recommendations include:
- Provide additional bedding or insulation.
- Increase weather protection for animals on vehicles.
- Delay the journey until there are warmer temperatures.
Read more & links
Further recommendations:
- Adjust flaps or windows and use protective sheeting to protect all animals from rain/snow and wind chill.
- Add extra weatherboards to protect animals from wind or rain.
- Keep animals as dry as possible. Shipment of wet animals may cause death from wind chill.
- Pre-warm vehicles by using heaters prior to loading, particularly for young animals.
- Prevent the freezing of drinkers and/or water lines by using heaters or adding mixtures (commercially available) such as glycerine and glucose to the water supply.
Relevant links
- Transport guide extreme temperatures – Pigs, factsheet EU Platform Animal Welfare, 2019
- Pig travelling, factsheet Animal Transport Guides Project, European Commission, 2018
- Guide to good practices for the transport of pigs, Animal Transport Guides project, 2017

Hot weather
Pigs have a very limited number of sweat glands, and therefore the major way pigs thermoregulate is via behavioural adaptation, e.g. pigs increase their respiration rate to lose heat.
High humidity will aggravate heat stress due to the reduced ability of the pigs to use evaporative cooling (e.g. by panting).
Read more & link
In hot weather, recommendations are:
- Increasing the space allowance by at least 30%.
- Provision of drinking water to animals as often as possible; provision of electrolyte solutions to pigs (required on long journeys).
- Use of climate controlled vehicles; sufficient ventilation must be available at all times while the animals are on a vehicle.
- Delay of the journey until there are cooler temperatures, e.g. at night.
- The use of showers, sprinklers or spraying systems, when the temperature is over 25 °C, to cool down the animals.
Relevant links
- Transport guide extreme temperatures – Pigs, factsheet. EU Platform Animal Welfare, 2019
- Pig travelling, factsheet Animal Transport Guides Project, European Commission, 2018
- Guide to good practices for the transport of pigs, Animal Transport Guides project, 2017
Importance of space allowance during transport

Space and welfare
The welfare of animals during transport is for a significant part dependent on the ability of the animals to stand and lie down, to adopt a normal position, to limit risks for injuries, stress or panic:
- Pigs may be motivated to lie down during transport, and after some time, they will do so if they have enough space.
- All animals on a vehicle should have sufficient space to lie down at the same time, as they have a strong tendency to synchronise their activities and resting moments.
Read more & links
Space and welfare continued ...
- Pigs are more capable of adapting to long (e.g. 550 km) transport conditions when loaded at a density below the present EU requirements.
- Whether animals will lie down depends on many factors. At some point it may be necessary for the animals to rest and to avoid states of fatigue or exhaustion.
Relevant links
- Note on minimum space allowance and compartment height for cattle and pigs during transport, Wageningen Livestock Research, 2014
- The effect of reduced loading density on pig welfare during long distance transport, Gerritzen et al., Animal 7: 1849-57, 2013
- Transport conditions of fattening pigs from farm to slaughterhouse, Gerritzen et al., Wageningen Livestock Research, 2012

Space requirements
Space allowance:
- Refers to the amount of space the animals have available in the vehicle during transport.
- May be expressed as kg of pig body weight per m² of surface area in the vehicle available to the pigs.
Read more & links
Requirements:
- Following Council Regulation EC 1/2005: “all pigs must at least be able to lie down and stand up in their natural position.” {Annex I, Chapter VII, D. Pigs}
- In order to comply with these requirements, the loading density for pigs of around 100 kg has been specified as not exceeding 235 kg/m² (0.43 m²/pig weighing 100 kg).
- More space is advisable, for pigs to be able to lie laterally and to lose heat (without contact to other pigs): between 0.72 and 1.01 m²/per pig of 100 kg.
Relevant links
- Do pigs have adequate space in animal transportation vehicles? Arndt et al., Front. Vet. Sci. 5: 330, 2019
- Guide to good practices for the transport of pigs, Animal Transport Guides project, 2017
- Note on minimum space allowance and compartment height for cattle and pigs during transport, Wageningen Livestock Research, 2014
- Council Regulation (EC) No 1/2005 on the protection of animals during transport and related operations, EC, 2004
- Lying characteristics as determinants for space requirements in pigs, Ekkel et al., Appl. Anim. Behav. Sci. 80: 19 – 30, 2003
- The welfare of animals during transport (details for horses, pigs, sheep and cattle), Scientific Committee on Animal Health and Animal Welfare, 2002

Deck heights
The space above the animal should be enough to ensure a normal standing position of the animal during transport. Additionally, deck height is important to ensure proper ventilation:
- There are no scientifically validated norms for optimum height. However, EFSA recommends that in non-ventilated vehicles 30 cm should be available above the withers, and 15 cm in ventilated vehicles. A minimum ceiling height should also be provided to rescue animals in emergencies.
- In current 5-deck vehicles used for transport of weaners this does not appear to be feasible.
Read more & links
The consortium of the Animal Transport Guides Project and the subgroup on transport of the EU Platform Animal Welfare recommend:
Deck height depends on the live weight of pigs and should be at least:
Live weight (kg) | Deck height (cm) |
<10 | 45 |
10 - 25 | 62 |
50 - 70 | 70 |
100 - 120 | 88 |
>120 | 100 |
Relevant links
- Transport guide extreme temperatures – Pigs, factsheet EU Platform Animal Welfare, 2019
- Guide to good practices for the transport of pigs, Animal Transport Guides project, 2018