Literature Review and Needs Assessment of Housing Systems for Gestating Sows in Group Pens with Individual Feeding
Group housing is a complex system, but it is one that the society is moving towards. There are many options in regard to choosing group housing for gestating sows. The housing systems from lowest to highest welfare are: tethers and stalls, indoor group housing then group housing with outdoor and substrate access. Electronic sow feeders (ESF) and individual feeders do not differ in productivity or physiological aspects of the pigs, but more injuries are seen when space is reduced. Competition increases when group size increases so additional feeders may be needed. Static sow groups experience less injuries and aggression compared to dynamic groups. Straw bedding is ideal for enrichment and positive sow behaviour. Fewer injuries and less maladaptive behaviours are noted when bedding material is provided. Thoroughly bedded sow housing systems experience a higher pregnancy and farrowing rate and less reproductive failure. Decreased feeding increases aggression, lesions and maladaptive behaviour so fiber can be used to increase satiety and prolong eating time. More research is needed on the effects of different feeding systems on productivity. Air quality improves when the floor is designed to not cause slipping. More research is needed on how to best manage group housing systems.