Laboratory mouse housing conditions can be improved using common environmental enrichment without compromising data

PLoS Biol. 2018 Apr 16;16(4):e2005019. doi: 10.1371/journal.pbio.2005019. eCollection 2018 Apr.

Abstract

Animal welfare requires the adequate housing of animals to ensure health and well-being. The application of environmental enrichment is a way to improve the well-being of laboratory animals. However, it is important to know whether these enrichment items can be incorporated in experimental mouse husbandry without creating a divide between past and future experimental results. Previous small-scale studies have been inconsistent throughout the literature, and it is not yet completely understood whether and how enrichment might endanger comparability of results of scientific experiments. Here, we measured the effect on means and variability of 164 physiological parameters in 3 conditions: with nesting material with or without a shelter, comparing these 2 conditions to a "barren" regime without any enrichments. We studied a total of 360 mice from each of 2 mouse strains (C57BL/6NTac and DBA/2NCrl) and both sexes for each of the 3 conditions. Our study indicates that enrichment affects the mean values of some of the 164 parameters with no consistent effects on variability. However, the influence of enrichment appears negligible compared to the effects of other influencing factors. Therefore, nesting material and shelters may be used to improve animal welfare without impairment of experimental outcome or loss of comparability to previous data collected under barren housing conditions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animal Welfare / economics
  • Animal Welfare / ethics*
  • Animals
  • Energy Metabolism / physiology
  • Environment, Controlled*
  • Female
  • Heart Function Tests / methods
  • Male
  • Maze Learning / physiology
  • Mice
  • Mice, Inbred C57BL
  • Mice, Inbred DBA
  • Nesting Behavior / physiology*
  • Nociception / physiology

Grant support

German Federal Ministry of Education and Research to the German Mouse Clinic (grant number Infrafrontier grant 01KX1012). Received by MHA. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The German Center for Diabetes Research (DZD e.V.) Received by MHA. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The German Center for Vertigo and Balance Disorders (grant number 01EO 0901). Received by TK. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.