Prediction of pork carcass composition based on cross-sectional region analysis of dual energy X-ray absorptiometry (DXA) scans

Dual energy X-ray absorptiometry (DXA) was used to measure pork carcass composition by performing a total scan of the right half of 262 pork carcasses (42.7±5.2 kg). The DXA scans were analyzed for percentage fat in the entire half-carcass as well as the shoulder, ham, loin, and side regions. In addition, a total of 14 cross-sections (57.6 mm wide) were analyzed: six in the shoulder/thoracic region, three in the loin region, and five in the ham region. Relative to the DXA measurement of total fat content, the coefficient of determination (R2) for a single cross-sectional slice ranged from 0.908 to 0.976. Relative to chemical analysis, a single slice from the ham region predicted the percentage of fat or lean in the half-carcass with an R2 of 0.81 and a standard error of the estimate of 2.04. Prediction equations were used to analyze a separate group of 65 half-carcasses. These results indicate that carcass fat and lean percentages can be measured by performing a single-pass cross-sectional scan that would be compatible with on-line processing.