Prediction of the in vivo Body Composition of Pigs Based on Cross- Sectional Region Analysis of Dual Energy X-Ray Absorptiometry (DXA) Scans

Abstract. The purpose of this study was to evaluate the use of a cross-sectional scan as an alternative to the total body DXA scan for predicting the body composition of pigs in vivo. A total of 212 pigs (56 to 138 kg live body weight) were scanned by DXA. The DXA scans were analyzed for percentage fat and lean in the total body and in 14 cross-sections (57.6 mm wide): 5 in the front leg/thoracic region, 4 in the abdominal region, and 5 in the back leg region. Regression analysis was used to compare total body and cross-sectional DXA results and chemical analysis of total body fat, protein and water. The relation (R²) between the percentage fat in individual slices and the percentage of total body fat measured by DXA ranged from 0.78 to 0.97 and by chemical analysis from 0.71 to 0.85, respectively. The relation between the percentage of lean in the individual slices and chemical analysis for percentage of total body protein and water ranged from 0.48 to 0.60 and 0.56 to 0.76, respectively. These results indicate that total body composition of the pig can be predicted (accurately) by performing a time-saving single-pass cross-sectional scan.