Towards healthy, productive genotypes

Selection for high productivity has been the long term focus of pig breeding programs worldwide, however, Rauw et al. (1998) highlighted that selection for productivity alone has unfavourable consequences for a number of metabolic, reproduction and health traits across species. More recently, Prunier et al. (2010) reviewed relationships between high physiological demands and the health and welfare in pigs, concluding that highly productive pigs have increased difficulties in coping with environmental challenges and are more susceptible to stress and disease through increased behavioural, physiological and immunological problems. As a consequence, it is becoming more important to implement breeding programs that optimise productivity across a variety of environments without any compromises in animal health and welfare of pigs. This approach relies on a balance between the resources available to pigs given environmental constraints and the requirements of the genotype for performance. In addition, heightened immunity levels and increased disease resistance can significantly reduce the undesired impact of environmental constraints on performance, health and welfare of pigs.