THE USEFULNESS OF A NEW TOBEC INSTRUMENT (ACAN) FOR INVESTIGATING BODY-COMPOSITION IN SMALL MAMMALS

Estimates of water mass, lean body mass (LBM) and fat content based on total body electrical conductivity (TOBEC) measured with ACAN-2 were compared with direct measurements of carcass composition in two specie s of rodents: the laboratory mouse (n = 20) and the bank vole (n = 14) . There was a strong linear relation between ACAN readings and lean ma ss or water mass. Body temperature did not affected the results, but t he readings were dependent on the species and sex of the individuals. That could be due to differences in the body shape. The accuracy of pr edicting an average LBM or water mass was very high (1.5%), but the er rors for predicting individual values were larger (8.5%). The predicte d fat content values have identical confidence intervals as that for L BM. However, the relative error for the prediction of the amount of fa t was higher, because the mass of fat was much smaller than LBM.