The Ability of SD-Rats to Distinguish Between Three Different Housing Environments

Abstract

Since 1986, when the Council of Europe gave the first provisions for housing of laboratory animals, the  focus on housing conditions has increased with emphasis on the size of primary enclosures such as cages or  pens as well as the complexity of the enclosure. Today European legislation dictates the minimum amount  of enrichment to be present in cages for different species. 

The aim of this study was to evaluate the influence of different enrichment schemes on growth rate, water  consumption, muscle strength and preference in rats, after items such as hides, nesting material, increased  cage height and shelves had been introduced to the cage environment. 

The study demonstrated that rats spend more time in the extra-enriched cages compared to the non-enriched  cages, whereas no differences in the dwelling time between the two types of enriched cages could be  detected. When present in the cage, the built-in shelf was used extensively (over 40% of the observations)  although no specific preference for the extra-enriched cage was detected. 

No differences in weight gain and water consumption could be detected between rats in the three different  housing conditions, although there was a slight increase in muscle strength for the standard-enriched housed  rats.