Submitted to: Journal of Animal Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/22/1997
Publication Date: N/A
Citation: Interpretive Summary: Dual-energy x-ray absorptiometry (DXA) was used as a non-invasive method to measure the composition of pig carcasses. DXA measurements of fat, lean, bone mineral and total tissue mass were compared with chemical analysis for fat, water, protein and total ash and scale weight. The mean value for total tissue mass by DXA was slightly less than the mean carcass weight . Although highly correlated, the DXA measurement of percentage fat in the half-carcass was significantly less than the chemical measurement. The DXA measurement of lean tissue mass was highly correlated with carcass protein and water content. DXA bone mineral content was more highly correlated with carcass weight than was carcass ash content. Using DXA region of interest analysis, estimates of the fat content of the shoulder and ham regions were close to chemical values, however DXA underestimated the fat content of the loin and side regions by 20 and 28%, respectively. Prediction equations were used to evaluate DXA measurements of the half-carcasses of 28 gilts and 37 boars slaughtered at approximately 120 kg. Based on these estimates the half-carcasses of gilts contained more fat, less protein and less water as compared to boars. These results indicate that DXA could be a valuable research tool for measuring the composition of pig carcasses. Based on the results of this study, prediction equations were revised for the DXA estimation of fat, protein, and water content of the half carcass and it appears that separate prediction equations are needed for regional analysis.
Technical Abstract: Dual-energy x-ray absorptiometry (DXA) was used as a non-invasive method to measure the composition of pig carcasses. The results of this study indicate that DXA can be used for determination of the fat, lean and bone mineral content of pork half-carcasses. Although the procedure is too slow for compatibility with on-line processing, for research purposes, when compared to dissection or chemical analysis, it offers speed, simplicity and potential accuracy. The present study demonstrates that DXA is capable detecting gender and genotype differences in carcass composition. Furthermore, improvements in accuracy are expected through refinement of prediction equations for both half-carcass and region of interest analysis.