Full title: Opinion of the FRCAW on the impact of partly or fully solid flooring systems on the welfare and behaviour of pigs.
Requested by: Compassion In World Farming (CIWF) France, Welfarm, Oeuvre d'Assistance aux Bêtes d'Abattoirs (OABA), La Fondation Droit Animal Éthique et Sciences (LFDA)
Date of request: 16/11/2023
Date of delivery by the FRCAW: 30/09/2024
Date of publication in English: 27/11/2025
DOI: 10.17180/rgz7-tsp7
Background to the request
Council Directive 2008/120/EC (European Council, 2008) prohibits routine tail-docking (partial removal of the tail) for piglets. The practice is permitted only when outbreaks of tail-biting occur on a pig farm and other measures have already been tried. Four animal protection associations (CIWF France, Welfarm, OABA, LFDA) have brought the following facts to the attention of the FRCAW:
- When their need to explore cannot be fulfilled, pigs tend to redirect it towards other pigs, resulting in tail biting.
- Tail docking is still routinely practised, despite Directive 2008/120/CE.
- Enrichment of their surroundings with litter and/or foraging materials is proving effective as a way to allow pigs to express their exploratory behaviours and thereby limit tail-biting.
- Provision of enrichment materials for sows allows them to express their nest-building behaviour.
- Fully-slatted flooring, the system most commonly used on pig farms, makes it hard to provide litter and/or foraging materials inside farm buildings.
The four animal protection associations, in their capacity as members of the Advisory Committee of the FRCAW, have asked the FRCAW to answer the following question: "What are the impacts of different solid flooring systems (partial/total) with or without the presence of bedding and/or foraging materials, on pig welfare and, particularly, on pig behaviours (manipulation, exploration, posture, interactions between animals, maternal behaviours, defecation behaviours) compared with a fully slatted floor? The FRCAW’s response will consider all categories of animal and all stages of development as defined by the pig industry". The FRCAW was also asked to examine further issues, in particular, the factors enabling optimal use of fully or partly solid flooring systems and the obstacles and levers relating to their installation on pig farms.
Main conclusions of the FRCAW
Impacts of alternatives to fully slatted flooring systems on the exploratory and nesting behaviours natural to pigs
The alternative flooring systems to a fully slatted floor are:
- partly slatted flooring (also known as partly solid flooring)
- bare solid floor
- solid floor, scraped litter (regular addition of straw, and scraping)
- solid floor, deep litter (a large quantity of litter is initially provided, to which further materials are regularly added)
The systems that provide the best welfare conditions for pigs are solid floors with raked litter or deep litter. These systems improve pig welfare because they are compatible with the distribution of large quantities of litter or forage. Litter and forage materials such as unchopped straw with long stalks (stalks > 7 cm) are the most effective materials to allow pigs to express exploratory and digging behaviours and to avoid the development of undesirable behaviours directed towards other pigs such as tail biting. The supply of 20 g of straw per pig per day reduces tail biting and the positive effect increases with the quantity supplied. Pigs’ exploratory behaviours are met by the provision of 200 g/pig/day. The optimal quantity to prevent tail biting is 400 g/pig/day.
For peripartum sows, long-stemmed straw is best-suited to a sow's nest-building needs. There is currently insufficient data to determine the optimal quantity to meet this need.
Fully slatted flooring does not allow adequate provision of litter as this would be likely to obstruct the gaps between the slats and block the effluent evacuation system. Partly slatted flooring is more suited to the spreading of litter than fully slatted systems, but is not optimal.
The FRCAW therefore recommends the preferred use of flooring systems that are fully compatible with the provision of long-stemmed litter and forage in large quantities, that is to say, solid flooring systems, when planning new buildings or renovating old ones.
Given that fully slatted flooring remains the most common system on French pig farms, the review suggests possible ways to adapt farming practices and modify buildings designed with slatted floors to provide animals with a better experience, while awaiting the opportunity to replace flooring systems when buildings are renovated.
Additional effects of solid flooring on pig welfare
Compared with fully slatted floors, solid or partly-solid floors increase the animal's sleeping comfort and their thermal comfort during periods of low temperature, allowing the animals to establish separate functional areas, as a consequence of the greater space available, and are associated with the reduction of the occurrence of lesions and wounds to the feet and lameness.
The positive impacts on these welfare criteria increase incrementally (fully slatted flooring < partly slatted flooring < solid flooring < scraped litter < deep litter) in relation to the quantity of straw supplied.
However, these flooring types require better management of the building atmosphere (ventilation) and a larger available surface area in order to control the cleanliness of the animals and their accommodation, their thermal comfort in hot weather and the risk of infectious diseases.
Obstacles and levers for the implementation of alternatives to fully slatted flooring
The expert report includes a table summarising the obstacles and levers for the development of alternatives to fully slatted flooring, which are essentially linked to socio-economic and environmental factors. To remove the concerns of some farmers over the financial viability and technical practicalities of transition to an alternative farming system, the principal identified levers include the sharing of success stories, training, the dissemination of research and development findings, and financial support from local and national government.
