Housing conditions modify seasonal changes in basal metabolism and body mass of the Siberian hamster, Phodopus sungorus

Abstract

Proper housing conditions are important aspects of animal welfare. Animals housed in enriched environments show less stereotypic behaviours than animals kept in barren cages. However, different types of cage enrichment may affect the results of experimental studies and hinder comparative analyses of animal physiology and behaviour. We investigated whether access to a running wheel, availability of nesting material, and pair housing affect basal metabolic rate (BMR) of Siberian hamsters (Phodopus sungorus) under various acclimation conditions. We used 70 adult hamsters (35 males and 35 females) divided into five groups housed under different cage conditions. All individuals experienced the same acclimation procedure: first a winter (L8:D16) then a summer (L16:D8) photoperiod, at air temperatures of first 20 °C then 7 °C under both photoperiods. We found that nesting material and pair housing did not affect hamster BMR, while access to a running wheel increased BMR and body mass regardless of photoperiod and ambient temperature. Thus, we suggest that cage enrichment should be applied with caution, especially in studies on energetics or thermoregulation, particularly in seasonal animals.

Fat accumulation in striped hamsters (Cricetulus barabensis) reflects the temperature of prior cold acclimation

“…A positive energy balance results in an excessive amount of body fat in relation to lean mass, which is usually induced by an increase in energy intake, such as hyperphagia for animals when fed with high-fat diet [ 13 , 14 ]. In contrast, a considerable decrease in food intake, and/ or an increase in energy expenditure may lead to the negative energy balance, and consequently the decreased fat store and lean body mass [ 15 – 18 ]. For example, Brandt’s voles ( Lasiopodomys brandtii ) and Mongolian gerbils ( Meriones unguiculatus ) increase energy intake in response to cold exposure but also exhibit significantly lower body mass and/or body fat [ 19 , 20 ].…”