A review of the welfare issues for sows and piglets in relation to housing

This review of sow welfare addresses all aspects of housing for adult femal e pigs, including the issue of piglet welfare during lactation. It puts the issue of sow welfare in perspective by briefly outlining different approac hes to the scientific assessment of welfare, the 'feelings, preference, nat ure, and the functional or homeostasis' approaches. We believe the last app roach currently offers science the best assessment of welfare and is the ap proach that is utilised in this review. It involves comparing housing or hu sbandry systems and risks to welfare on the basis of relative changes in bi ological (behavioural and physiological) responses and corresponding decrea ses in fitness (growth rate, reproductive performance, or health/injury/imm unology). The review discusses the following areas: (i) housing of individually house d pregnant pigs, with subsections on tethers, stalls, reproductive performa nce, exercise, and new stall designs; conventional, alternative, and outdoo r group housing with subsections on aggression, electronic feeding stations , ecoshelters, and other alternative group housing designs; and other issue s, such as lameness, culling, straw and other substrates, diet and hunger, quality of stockpeople, and housing around mating including oestrus detecti on and mating; and (ii) farrowing and lactating pigs with subsections on fa rrowing crates and alternative farrowing systems, stress around farrowing a nd during lactation, maternal behaviour and piglet survival, and sow and pi glet injury and lameness. Conclusions and recommendations arising from the review include the need fo r public education to provide an informed consumer base that will result in some consensus on welfare issues among diverse interest groups and the nee d for industry education that results in better animal welfare and a sustai nable industry. Some specific research recommendations include space allowa nce and the duration of housing for individually housed pigs, welfare issue s of breeding sows in echoshelters, piglet mortality in alternative systems , aggression in conventional and large groups, bedding, and hunger.