Miniature pig (minipig) has been considered as an important laboratory animal in the developmental biotechnology researches with respect to xenotransplantation, stem cell, somatic cell nuclear transfer and embryo transfer. Given that the laboratory minipigs are normally housed at an indoor facility, they pass the time with lying or sleeping unless it is feeding time. Therefore, it is necessary to provide environmental enrichments to satisfy their innate needs and to lessen atypical behaviors caused by stress, on the purpose of welfare. We quantitatively investigated the type of preferable enrichment for the laboratory minipigs as well as its effect on their daily life. They presented a great interest to the pliable pail but a rapid loss of attraction to non-preferable enrichments. When the daily life of the single housed minipigs was quantified based on duration of playing or resting, they were more actively engaged in lively activities in the presence of enrichments. In addition, the provision of enrichments could effectively alleviate the conflicts during group housing when new pen mate was introduced, resulting in reduction of wound cases. We believe the considerations of animal welfare are essential to the conduct of better research because animals in the non-stressful environment will be more physiologically stable and provide more reliable results in the animal experiments.

Minipigs are regarded as one of the most important laboratory animal in that anatomical and physiological properties are similar to human and their reproduction efficiency is relatively higher compared to other large animal species. Particularly, several diseases that cannot be mimicked in rodent models are successfully occurred or induced in pig models therefore it has been interested in a valuable model for human diseases. Pigs are also ‘standard’ species in xenotransplantation research. To maximize experimental outcome using minipigs, establishment and management of proper animal facility, right animal husbandry and control of pathogens are very important. In this review, we summarized several international guidelines related with minipigs published by several companies or governments and discuss optimal conditions for providing informative ideas to the researchers who want to use minipigs in their future studies.