Paddock management systems for organic growing pigs: Effect of land allocation strategies on foraging activity and excretory behaviour

Summary

The EU regulations for organic farming require outdoor access for pigs, as one of the main organic principles is to establish sustainable farming systems including harmonious relationships between animals, plants and environment. Outdoor access for pigs provides benefits in terms of animal welfare as pigs are able to express their natural and social behaviour. However, it is still common to keep organic growing pigs indoors with access to outdoor concrete yards.
Main reasons for not keeping growing pigs on pasture are high nutrient inputs to the free-range area and high feed costs due to an increased energy demand in outdoor pigs. Reasons for the high nutrient loads on free range areas are the not-random excretory behaviour as well as the high input of supplemental feed. The reduction and better distribution of nutrients on the field can be achieved by different strategies. Considering the excretory behaviour and foraging activity of pigs the main focus in this study was to identify suitable environmental friendly paddock management systems for organic growing pigs with high animal welfare standards.
For identifying those, an experiment with growing pigs was conducted in Denmark. Within this experiment growing pigs got access to two strategies of land allocation. They got either access to 3x12 m of new land right away (allocation strategy 3) or to 1x12 m of new land on three days in a row (allocation strategy 1). In combination with new land they got one of the forage crops alfalfa or grass-clover and access to either high or low protein content in the supplemental feed. During the experiment behavioural observations were performed. Rooting, grazing, urinating and defecating were recorded to investigate the effect of management system on the pig’s behaviour.
It was shown that pigs are rooting and grazing significantly more often in new land. However, urinating in this study is performed to a significantly lower extent in new land compared to old land. The allocation strategy affects foraging activity and excretory behaviour when the three observation days are regarded separately.
From the present study it became clear that paddock management strategies should be based on mobile systems including frequent allocation of new land, e.g. strip grazing or pasture rotations and mobile huts, feeders and drinkers. An interesting approach is to establish mobile paddock systems such as the mobile organic piggery (MOP). Nevertheless, more research in the field of paddock management systems is required. In particular more knowledge on mobile fence systems is necessary to make these systems common on farms.