Breeding for improved welfare of growing pigs

Abstract

Welfare should be considered in pig breeding programs. A number of welfare traits related to pork quality, health and survival of pigs have already been included in pig breeding programs and this list of welfare traits should be extended further. It is important to provide the best-possible environment to pigs on farms. Animal breeding can contribute to this aim indirectly by providing descriptors of environmental conditions from genetic analyses of performance traits which can be used for assessment and optimisation of husbandry practices. Further, selection for improved disease resistance reduces pathogen load in the environment. Maintaining good welfare for all pigs on farms all the time requires a detailed monitoring system which has been provided by the Welfare Quality® (2009) protocol. The 12 welfare criteria defined by the Welfare Quality® (2009) protocol provide guidance for the genetic improvement of welfare in pigs. Genetic variation exists for numerous traits related to these 12 welfare criteria. For example, genetic variation was found for the number of shoulder ulcers in sows which is an important welfare trait of sows. Selecting pigs with less skin ulcers may also offer opportunities to improve comfort of growing pigs. Growth is an important performance trait which is affected by the health status of animals. Therefore, growth has been used as a proxy for health which affects the welfare of pigs. For this purpose, it is important to record growth of all animals including sick pigs to better identify pigs with health and welfare problems. This will also enhance estimates of indirect genetic effects for growth which may be a selection strategy to improve behaviour of group-housed pigs and reduce the incidence of tail biting. Indirect genetic effects quantify the heritable component of the social effects a pig has on performance of its group mates. Multiple factors and traits affect and describe welfare of pigs and numerous avenues are open for pig breeding to further improve welfare of pigs on farms.