Future outdoor runs for organic slaughter pigs will benefit both the pigs and the environment.

From: Linda Rosager Duve, Communications Officer, Innovation Center for Organic Farming

Organic slaughter pigs have access to an outdoor run year-round, and there is great potential to improve it further.

An outdoor run typically consists of a concrete area, where at least half of the surface is with a solid floor and the rest with slats. The outdoor area is usually partially covered, allowing the pigs to go outside and get fresh air, daylight, and stay dry at the same time.

The outdoor run functions as a space for resting, relaxing, and activity, but the pigs do not necessarily use all parts of the area as intended. This can mean that they rest, root, and defecate in the same places, which can both affect animal welfare and increase the risk of ammonia emissions.

The future outdoor run should be arranged more so that pigs naturally choose different areas for resting, activity, and defecation. This can both improve animal welfare and reduce environmental impact. But how do we optimize the outdoor area so that it better meets the pigs' needs, and how do we motivate the pigs to use the area correctly?

This question was the focus of a workshop recently held by the Innovation Center for Organic Farming in the PENMAP project, where researchers, organic slaughter pig producers, and advisors jointly develop the outdoor run of the future.

The participants in the workshop came up with a wide range of ideas on how to arrange the outdoor run so that it supports the pigs' natural behavior, considers the environment, and is manageable for producers.

The outdoor area should invite pigs out

As mentioned, organic slaughter pigs have access to an outdoor run, but how it is arranged has a significant impact on how the pigs use it.

One of the main points from the workshop was that the outdoor run should make it intuitive for pigs where to rest, be active, and defecate. If it is successful in separating these different behaviors, it can both improve animal welfare and make it easier to limit ammonia emissions from the outdoor run. At the same time, it is important that the solutions do not simply move the defecation area into the barn.

The pigs' needs change with the seasons

The discussion at the workshop led to the conclusion that shade, ventilation, sprinkling, and other cooling options are crucial in summer, while shelter and a dry resting area become more important for thermoregulation in winter. Therefore, more coverage and a well-bedded resting area were among the suggestions.

The resting area should offer:

·       a shaded and soft bed in summer

·       shade and shelter as well as an insulating substrate in winter

Shade was also a major topic in the discussions. Several producers experience sunburn in slaughter pigs, especially light-colored pigs can be vulnerable. Therefore, both more shade and the creation of wallows were mentioned as possible solutions, provided they can be integrated without creating new environmental challenges. In winter, wallows are not necessary, so it is important that the wallow area can be converted into, for example, an activity area during winter, so it still has value for the pigs.

Wallow areas can be created by installing a border and a mat under the sprinklers, and then adding soil one or more times daily. The soil will turn the water puddle into a mud bath, which cools the pigs, provides sun protection, and allows the pigs to root in the soil. Rooting in soil is something many find highly motivating for pigs.

In winter, the mat in the mud area can be removed, and materials like wood chips or other rooting materials can be added. This way, the area functions solely as a rooting zone in winter, while in summer it serves both as a mud hole and a rooting trough.

A good resting area encourages pigs outside

An attractive resting area is an important prerequisite for pigs to choose to stay outdoors. Therefore, the design of the resting area was a major focus in the workshop. The participants agreed that a soft and dry bed under a shelter can make the outdoor run more attractive year-round. At the same time, the resting area should be clearly separated from the areas where pigs root and defecate. If the bedding area is too large, there is a risk that the pigs will start to defecate in parts of it. Conversely, a larger resting area can reduce aggression among pigs, so a balance between these considerations is necessary.

Several pointed out that the size of the resting area can be advantageously adjusted according to the pigs' size throughout the production cycle. Solutions with entrances and exits at both ends of the resting area were also suggested, so that pigs do not get trapped at the back and choose to defecate there. It was also emphasized that the bedding material should be uniform and not encourage rooting behavior. Sand in summer and straw in winter were among the materials mentioned. Several participants also noted that pigs prefer to lie against a wall where they feel protected.

Another idea was a resting area under a raised platform. The platform provides shade in the resting area and can be equipped with brushes for skin care on the area above the resting zone. At the same time, a platform adds environmental variation for the pigs. The platform can be placed on wheels and anchored to the floor. Its placement can thus create additional variation, and the ability to move the platform makes cleaning the area easier.

Fresh rooting material maintains interest

Rooting behavior is an important part of pigs' natural behavior, but workshop participants agreed that pigs quickly lose interest if the material is the same day after day.

Solutions were proposed where rooting materials such as straw, branches, compost, fresh grass, soil, or wood chips are continuously replaced or supplemented. Several also pointed out that pigs are motivated to work a little to access a reward—such as searching for feed or activating simple enrichment elements. Longer-term enrichment can also help reduce aggression among pigs.

For example, pigs can be activated with a ball hung up so it doesn’t get soiled. The ball can contain carrots or other rewards, where pigs have to work to access the reward. The contents can be varied to ensure novelty, and the ball can possibly only be available part of the time.

Small details can influence defecation behavior

The workshop also showed how complex pig behavior is. Pigs typically avoid defecating near functional resources. For example, pigs usually do not defecate where they eat. This means that the placement of functional resources (e.g., roughage) can be used actively in the design of the outdoor run. But it requires that the resources have a function for the pigs. They must be attractive, so it is important that, for example, roughage is provided frequently in small amounts so that pigs do not lose interest.

Participants also pointed out that pigs often defecate shortly after getting up from a resting period, and often choose to go a short distance from the resting area before defecating. Some also believe that pigs often take a small detour to defecate when moving from one point to another, so it is crucial to consider both the pathways for the pigs and opportunities for manure removal in the design of the outdoor run.

The next step is practical testing

The workshop marks the beginning of development work in PENMAP, and the many ideas will now be translated into concrete solutions, which will first be tested in a pilot trial with a producer. During the pilot, there will be opportunities to adapt and optimize the different zones being arranged in the outdoor run. Subsequently, a scientific evaluation will be conducted to document the importance of multiple functional zones in the outdoor run for pig welfare and use of the area. The project runs until early 2029, and the goal, as mentioned, is to develop future outdoor runs where high animal welfare and environmental considerations go hand in hand – for the benefit of pigs, producers, and the environment.