Group sow housing and which system to choose

By Scott Wiggill, Big Dutchman

Group sow housing systems have been in the spotlight over the past few decades, due to pressures from Welfare Organisations as well as food distribution chains promoting good animal welfare to consumers.

We have seen this trend being implemented in Europe and other countries, including South Africa. With local producers being accustomed to traditional crates in South Africa, there is a lot of negative perception about group sow housing with regard to sow production, as well as the capital layout required for such a change. It can be discouraging for the producer, especially during the current market conditions of high input costs and low meat prices.

Traditional crates have served their purpose of confining the animal in order to minimise fighting, thus ensuring embryonic implantation during the first 42 days. The management of crates has been fairly easy with regard to heat detection and controlled feeding, but the challenge lies in implementing the above in a group system.

Some consolation to local producers is that group sow management systems have been successfully tried and tested throughout the world. If one is planning a new gestation house, now would be the right time to start with loose sow housing systems, to avoid additional capital expenditure before the expected deadline.

Fortunately, the code of conduct has allowed for a maximum of eight weeks of early gestation in crates, with the last eight weeks in groups. This has also given the producer the flexibility of having crates for the first six weeks or earlier, with the remainder of the gestation period in group systems.

The purpose of this article is to explore the various types of group sow production systems available, including their advantages and disadvantages, with the intention of helping the producer select the system that best suits their farm’s individual needs, with the objective of maximising sow performance.

When looking at the various systems available, one needs to consider the following guidelines:

  • Floor space per sow – legislation is stipulating a minimum of 2.25mÇ/sow to 2.5mÇ/sow depending on the size of group.
  • The ratio of crates versus groups housed (early gestation: late gestation)
  • Number of sows per group.
  • The effect of dominant sows and the hierarchy structure of the group.
  • Genetic potential of the animal with regard to different rations fed at different stages of pregnancy.
  • Gilt introduction into pens. With certain systems, gilts need to be trained.
  • The environment of the building with regards to animal comfort and ventilation.
  • Suitable non-slip flooring and adequate concrete slats with apertures not wider than 18mm.
  • Hospital pens – for injured, lame and sick animals.
  • Animal flow with regard to entry and exit of sows.
  • Good hygiene and ease of cleaning

Legislation has permitted sows in gestation crates to a maximum of eight weeks, thus allowing the versatility of keeping sows in crates for a smaller period, depending on producer preferences.

The various systems available worldwide are the following:

Group pens

This involves keeping small to medium size groups in one pen. In South Africa, this seems to be the most preferred system as it is the most cost effective solution. Sows are kept in groups of 6 – 20 sows per pen and the system involves a fairly simple layout. Sows are fed simultaneously and the manager can quite easily supervise the animals during feeding.

The challenges of this system involve the accuracy of feeding, as one cannot allocate a specific volume dispenser to a sow, as they may eat in different sections at different feedings.

When taking the above into consideration, there has been a trend towards group sows in smaller groups (six to eight sows), in similar weight groups, where one can set an average feed quantity on the volume dispensers.

However, a dominant sow will normally finish her feed quicker and will start fighting with other sows for more feed.

Certain structural designs have been made to avoid this from happening, such as installing shoulder boards and thus preventing visibility between sows during feeding, as well as installing down pipes close to the floor, causing the feed to bridge and thus making the sow work for its feed whilst eating, and slowing them down.

Group housing with single stalls

This is a system where the sow feeds in crates that are manually closed, and after feeding the crates are then manually opened to allow the sow to exit and move freely between other sows.

This system involves manual labour of opening and closing the crates, and the capital layout of such a system can be quite costly, as one must make provision for crates as well as extra floor area behind the crates where animals can roam according to legislation.

Sick animals can be left in a crate to allow for adequate recovery.  This system has been successfully practised quite extensively in most European countries.

Free access stalls

This is a system where the sow can enter and exit the crate at her own will. The design structure of the crate closes automatically when the sow enters for a feeding, thus preventing competition from other sows, and she can then exit by pushing the back gate open herself.

The crate also acts as an individual retreat for sows that are being bullied, as well as an ICU crate where the manager can lock a crate for injured animals allowing for adequate recovery.

This system is probably the most expensive option due to the design structure of the crate, as well as the cost of floor space required, but can be a very good option to consider as the management hereof is similar to gestation crates that producers are currently accustomed to.

Electronic sow feeding on demand

(ESF systems)

This is the most advanced sow feeding system available on the market. The system involves identifying the sow by means of an ear tag where information is transmitted to the station on how much feed to give. This information is entered into the computer program by the manager, based on the sow’s condition.

The other added advantage is record keeping of the animal, including statistical data, which can assist in decision making. All information is then transmitted between the station and a central PC through our animal software – “Big Farm Net” – which makes management and record keeping of the system fairly simple.

This system involves intensive training of gilts and sows, but once the animal is trained, the management of the system becomes easy. ESF systems are quite versatile where it can handle groups of up to 60 sows per station, and depending on the size of the unit, the building layout can be set up to accommodate weekly groups in a stable group (1 250 sow unit and bigger) or in dynamic group (units ranging from 100 sow unit up to a 1 000 sow unit), where all sows from different stages of pregnancy are mixed together with the station, knowing the exact information for each animal entering, and then automatically selecting them out into a central passage prior to farrowing.

Floor layout and penning of an ESF application plays a very important role, where provision must be made for a roaming, as well as a sleep area, where penning is manipulated to provide refuge should aggression occur. A hog detection pen can be installed to detect sows coming back on heat.

Worldwide statistics of ESF systems are proving to have less aggression as the level of hierarchy plays a smaller roll in larger groups.

There have been several of these systems installed in South Africa, where Big Dutchman have successfully completed two installations, both in dynamic and stable applications, and are preparing for our next installation on the Greenfields project, involving a 650 sow unit in the Western Cape, where sows will be placed on ESF’s directly after mating.  This will be a first for South Africa.

Whatever the customer preference, in terms of the above mentioned systems, Big Dutchman have the expertise, both local and international, to meet the customer’s needs.

In my personal experience, it is rewarding to see how group sow housing has progressed and how it has improved the well-being of animals. I trust that you as the producer will also be impressed.