Total body electrical conductivity (TOBEC) measurements in Mongolian gerbils (Meriones unguiculatus) and golden hamsters (Mesocricetus auratus).
Weinandy, R. and Gattermann, R.
Journal of Experimental Animal Science, 42(1), 21-30 (2002).
Body composition of adult Mongolian gerbils (Meriones unguiculatus) and golden hamsters (Mesocricetus auratus) was determined using the non-invasive measurement of the total body electrical conductivity (TOBEC). A regression model was developed based on direct chemical analysis of the carcass and calibration equations were defined to predict the fat-free mass (FFM) and the total body water (TBW) in these two species. The closest correlation was obtained by calculating a linear regression of FFM and TBW as a function of TOBEC: gerbils: FFM (g) = 0.20548 × TOBEC + 10.0224; TBW (g) = 0.14485 × TOBEC + 6.51824; golden hamsters: FFM (g) = 0.18043 × TOBEC + 18.5806; TBW (g) = 0.14817 × TOBEC + 4.50379. Based on these equations and the respective TOBEC values, the body composition was analysed. Male golden hamsters had a higher crude fat mass (CFM, obtained by substracting the FFM from the body mass) and a higher dried body mass (DBM, obtained by substracting the TBW from the body mass) than females, which had a higher percentage of FFM and TBW. In Mongolian gerbils, males had higher CFM, higher DBM and the absolute FFM and TBW was elevated. As in female golden hamsters, female gerbils had a higher percentage of FFM and TBW. Results are discussed in relation to the usefulness of this non-invasive technique, which allows repeated individual measurements of body composition. It helps to reduce the number of animals necessary when estimating body condition and welfare issues, male/female differences or for the evaluation of seasonal effects and housing conditions.