Group gestation sow housing with individual feeding—II: How space allowance, group size and composition, and flooring affect sow welfare

Abstract

Group sow housing can be a complex system and facilities come in many forms. At present, there is a lack of research adequately comparing all of the different options available for the group housing of gestating sows. The aim of this review is to assess current research findings and highlight further areas of research that are required to provide producers with information about which group systems best promote sow welfare and productivity. Specifically, the objective of the review was not to compare the use of gestation stalls versus group sow housing, but to take an in-depth look at group sow housing systems which utilize individual feeding methods (protected and unprotected) and to conduct a research needs assessment with particular attention regarding sow welfare. Generally, aggression at mixing and competition for feeder entry are the primary welfare challenges in ESF-fed sows. Increasing group size in an ESF system has different implications than in a system with feeding stalls. Low ranking sows were found to be at a disadvantage in both static and dynamic groups, especially in an ESF system, as these sows received more aggression and injuries, while also exhibiting poorer productivity compared with high-ranking sows. A review of the scientific literature reveals a need for direct comparisons of individual feeder types with consideration for interactions between group size, composition, space allowance and enrichment materials in group housed sows.