The welfare of pigs and minipigs

Abstract

The welfare of pigs is usually discussed in relation to animal production. Nearly all pigs are bred for the purpose of food production, often compromising welfare in favour of economical considerations (SchroderPetersen and Simonsen 2001). However, during the last two decades, pigs have increasingly been used as research animals, mainly because of prospects of xenotransplantation, but also as alternative non-rodent models in regulatory toxicology (Bollen and Ellegaard 1997). In Denmark, the use of pigs in biomedical research has increased by more than 500% from 1980 to 2001. Nevertheless, overall pig use is about two percent of the total number of animals used in biomedical research (Danish Animal Experiments Inspectorate 2001), which is insignificant compared to numbers of pigs in food production. Similar figures are seen in European statistics. In 1991, 48,420 (0.41%) pigs were used in biomedical research in the member states of the European Union, whereas this had increased to 6,749 (0.56%) in 1996 and 66,131 (0.67%) in 1999 (Commission of the European Communities 2002). Animal welfare is a topic of concern in biomedical research. Apart from moral concerns and legislative obligations to secure good welfare for animals kept at the laboratory, a reduced animal welfare makes the results from biomedical research with animals unreliable (Van Zutphen et al. 1993). Moreover, when pigs are going to be used as organ donors, an optimal organ quality can only be guaranteed from a healthy, non-stressed pig (Olsson 2000).