Developing a group housing system for lactating sows and their litters

Group housing of gestating sows has become mandatory in the EU due to welfare concerns about individually confined sows. During lactation, however, most sows are housed in farrowing crates. A multi-suckling (MS) system provides a larger and more complex environment with more possibilities to express natural behaviours. By housing several sows together with their litters, MS-systems can enhance piglet social development and have the potential to stimulate socially facilitated eating behaviour. MS-systems, however, also pose risks including disrupted nursing behaviour and increased piglet mortality. Thus, MS-systems can provide both advantages and disadvantages for sow and piglet welfare. In the Netherlands, a new MS-system for five sows and their litters has been developed, in which sows can move freely and piglets can enter the communal area after 1 week of age. The system includes a communal floor-feeding area where piglets can learn to eat from the sows. MS-raised piglets showed indicators of improved pre- and post-weaning development. Pre-weaning mortality, particularly before mixing litters, was however an issue that needed attention. In a new version of the system, this issue will be addressed. In addition, in future experiments we will investigate performance of sows and piglets during a 9-week lactation period in which a more gradual weaning process is stimulated using intermittent-suckling.