The welfare of growing-finishing pigs

The growing-finishing (G-F) period in commercial swine production represents the phase of production with the longest time and greatest opportunities for improvements in pig performance, health, and welfare. Many factors impact directly or indirectly on the welfare of the G-F pig. Weaning is one of the most traumatic events that piglets experience in most commercial production systems. Factors that contribute to both acute and chronic stressors experienced by the individual piglet are changes in their nutritional supply, changes in their accommodation and mixing of 'foreign' piglets. All can have consequences on the piglets' physical, immunological and psychological status. A plethora of research indicates that early weaning age is strongly related to certain behavioural and physiological problems that some piglets express. Such deviations away from baseline piglet behaviour involve increased expression of vocalisations, belly nosing and aggressive interactions in the first few days following weaning. Applying elements of the pre-weaning environment to the post-weaning environment will ease the stress of weaning. These elements include milk replacer, maternal pheromones and physical environmental enrichments. The most direct influences on pig welfare throughout the grow-finisher stage are the quality and quantity of human interactions, management practices, facility design, genotype, and the health of the pigs. Attention is being focused toward 'alternative' systems (pasture, deep bedded or hoops) and how this filters into premium or niche marketing for producers. Future research areas need to focus on the opportunities for improvement of animal welfare through environmental enrichment, space allowances for the finisher pig and pig handling/people training. In conclusion, the addition of environmental enrichment or the use of alternative production systems for the grow-finisher pig provides an opportunity for premium marketing and enhanced animal welfare of the livestock. The success of these systems will depend on customer and consumer demand for premium products and environmental adaptations of a producer with an appropriate production system.