The choice of floor type will depend on a number of factors: the needs of the herd, the method being used to manage droppings, straw availability and labour availability. Further, target ACA standards (European standards, biological, certified human, etc.) will also play a factor in the type of floor chosen. In Canada there are currently no standards for the type of floor or concrete slats that must be used in group-housing gestating sows.

Ferme porcine L.V. Inc. Original floor under sow stalls was used. A metal strip was installed to cover large gap between slats.

Flooring with narrower gaps and slats seems to reduce feet lesions and increase the standing comfort of the sows while not significantly impacting the ease of manure removal.

What are the most effective concrete floor slat and gap width ratios for comfort and well-being of sows as well as ease of manure management?

Based on detailed evaluations of different slatted floor configurations, two flooring types were evaluated in group pens holding sows over two gestation periods:

  • Test floor: slats at 105 mm (4”) with a gap of 19 mm (0.75”) (slightly narrower than commonly used)
  • Control floor: Slats at 125 mm (5’’) with a gap of 25 mm (1’’) (typical in commercial barns)

Overall, when measuring sow lameness, behaviour, reproductive performance and culling rates, there were minimal differences seen between sows evaluated on the test floor versus the control floor. However, sows on the test floor had fewer feet lesions and showed less hind-limb discomfort than those on the control floor. Evaluation of air quality, sow cleanliness and floor friction demonstrated that manure removal was not compromised by the narrower gaps and slats of the test floor. In addition, researchers evaluated the physical properties of rubberized and synthetic concrete overlay materials. The rubber overlays tested were softer than concrete which would increase sow comfort, and had greater surface friction which would reduce slippage. Additionally, the overlay materials had similar bacteria counts as concrete after pressure washing. While the material showed good resistance against pressure washing, more study would need to be done to assess its durability and longevity.

Fully or Partially Slatted Floors

Floors in the pen-gestation sections can be completely slatted or of solid concrete surfaces, in strategic areas. It is important to remember that sows prefer to lie down on solid concrete surfaces and these surfaces need to be located in areas where it is desirable for them to lie down. Optimizing flooring and social management of group housed gestating sows

Slatted Floors

Concrete slats make it easier to manage the removal of manure and require very little clean-up time. They also mean drier surfaces, thereby avoiding injury due to slipping. On the other hand, the risk of injury (e.g., dew claws) resulting from fighting is greater.

There are other very important points to be aware of when it comes to using concrete slats in order to avoid problems relating to standing/lameness among group-housed gestating sows:

  • The edges of the gaps between slats must not be too sharp because if they are, there is increased risk of injury to the feet.
  • The slats need to be installed properly in order to avoid height differences between the slats and also to prevent movement when they are being walked on.
  • The European Union (EU) standard for maximum gap width is 20 mm.
  • Note re new floors: Ensure that there are no rough edges as these will cause hoof lesions (check edges around the gaps, and file these areas before introducing sows if necessary).

Slats tend to wear with use, and the gaps widen; this increases the risk of injury to the dew claws because they go deeper into the gap. It is also important to ensure, as in the case of new floors, that the slats comply with prescribed standards and are laid correctly in order to avoid height variations.

Solid Concrete Floors

Solid floor surfaces should be installed only in lying areas, because sows prefer to sleep or lie on solid surfaces.

Recommended areas for locating solid floors

  • Floor feeding – Feeding/lying areas
  • Shoulder stalls – Only under the troughs—avoids wastage of feed
  • Free-access stalls –  In the front part of the free-access stall / common sleeping/lying areas
  • ESFs – Sleeping/lying areas
  • Free access ESFs – Sleeping/lying areas

With solid floors, controlling ambient conditions is essential in order to avoid harmful drafts in the sleeping areas and having the sows relieve themselves there, resulting in a lack of cleanliness.


Bedding provides material that the sows are able to manipulate and chew on and thereby express their need to root.5 Also, bedding generally promotes good standing ability among the sows. However, it must be of good quality and readily available at a reasonable cost, which is not always possible because it is becoming more and more difficult to find on the market at an affordable price.

There are two possible ways to manage bedding, i.e. raking (removal of droppings two to seven times per week) or leaving them to accumulate (removed once a month or after a gestation cycle). To work properly, straw-based systems require a greater amount of floor space per animal than on a slatted floor. According to European standards, that amount of space needs to be 3 m2/sow (32.3 ft2/sow) on a raked bed and 3.5 m2/sow (37.7 ft2/sow) on a bed where droppings are allowed to accumulate. Failure to meet these floor-space requirements will affect the amount of straw needed per sow, because the straw becomes soiled more quickly. On average, 1.7 kg (3.75 lb.) of straw/sow/day are required when using the raked-bedding system and 2.4 kg (5.30 lb.) of straw/sow/day are required when droppings are left to accumulate.

However straw bedding requires an increased workload because handling it (distributing, scraping and managing manure) requires a great deal of time and it cannot always be completely mechanized. It also requires larger buildings, not only for the sows, but also for the storage of straw and manure. Recent Danish barn designs provide drainage holes with a chain scraper under bedded floors. In this system the bedding remains dry and requires less maintenance. Producers are required to completely clean the pens one per year.