Electrical Conductivity to Predict Body Composition of Mammals and the Effect of Gastrointestinal Contents

Evaluation of Total Body Electrical Conductivity to Estimate Body Composition of a Small Mammal

“…We expected the higher percentage of error of the fat compartment relative to water or lean mass compartments because fat levels often show the highest level of inter-individual variability (Widdowson 1965, Robbins 1993. Compared with other published studies, we had a lower percent error (Asch andRoby 1995, Zuercher et al 1997) and similar (Bailey 1979, Meijer et al 1994, Fischer et al 1996 or higher (Roby 1991, Voltura andWunder 1998) accuracy of predictive equations.…”

“…We placed a removable plastic, split-ring band (H.C. Hughes, Ltd.) on each individual so that bats could be housed together in cloth bags until we made TOBEC measurements. Although gut contents do not introduce significant errors in body composition estimates (Voltura and Wunder 1998), we made all TOBEC measurements after 1300 hours when most of the gut contents had been voided. We allowed bats to cluster in a wooden holding cage (Kunz and Kurta 1988), and we completed all sampling by 1400 hours to reduce potential influence of dehydration.…”

“…Total body electrical conductivity can directly measure lean body mass, although many studies have used this technology only to estimate body fat by subtracting lean body mass from live mass. This approach, however, is often of limited value because small measurement errors in lean mass produce large relative errors in estimates of body fat due to its smaller compartment size (Morton et al 1991, Skagen et al 1993, Voltura and Wunder 1998. In addition to the potential for high estimation error in the fat compartment, TOBEC is sensitive to variation in both ambient temperature (Klish et al 1984, Roby 1991) and body temperature (Walsberg 1988, but see Roby 1991).…”

Prediction of Body Composition of Live and Post-Mortem Red Foxes

“…The coefficients of determination for models predicting mineral masses were lower than the others. This may depend on an increased difficulty for predicting the mass of a small body component (ഠ5%; Zuercher et al, 1997;Voltura and Wunder, 1998). The lower precision of mineral predictions has limited consequences because this body component plays a minor role in the bioenergetics of mammals.…”

“…Other studies on the estimation of body components of live mammals concerned mostly body water or fat and utilized TO-BEC, BIA or IWD in addition to body mass to estimate water or fat mass (Farley and Robbins, 1994;Zuercher et al, 1997;Hilderbrand et al, 1998;Voltura and Wunder, 1998). Gerhart et al (1996) used body score to estimate fat content of caribou whereas Jopson et al (1997) utilized X-ray computed tomography to estimate the mass of body fat, muscle and bone in fallow deer (Dama dama).…”