Dual-energy X-ray absorptiometry measurements of the body composition of pigs of 90- to 130-kilograms body weight.

We used the pig as an in vivo model for evaluating the effects of extreme body depth on the measurement of body composition by dual-energy X-ray absorptiometry (DXA). One group of 17 pigs weighed an average of 90 kg and had a maximum body depth of approximately 30 cm; another group of 54 pigs weighed 123 kg on average and had a maximum body depth of about 35 centimeters. In the larger pigs, DXA tended to measure a higher percentage of total body fat relative to the chemical analysis than in the smaller pigs. In both groups, but more predominantly in the larger pigs, there were areas in the bone of extreme thickness and/or density that were excluded from the analysis, which caused underestimation of bone mineral content and total tissue mass.