Calibration of an on-line dual energy X-ray absorptiometer for estimating carcase composition in lamb at abattoir chain-speed

• Published in: Meat science 2018-10, Vol.144, p.91-99
• Main Authors: Gardner, G.E., Starling, S., Charnley, J., Hocking-Edwards, J., Peterse, J., Williams, A.
• Format: Article
• Language: English
• Subjects: Accuracy; Automation; Computed tomography; Genetics; Precision
• ISSN: 0309-1740; 1873-4138
• DOI: 10.1016/j.meatsci.2018.06.020

This experiment assessed the ability of an on-line dual energy x-ray absorptiometer (DEXA) installed at a commercial abattoir to determine carcase composition at abattoir chain-speed. 607 lamb carcases from 7 slaughter groups were DEXA scanned and then scanned using computed tomography to determine the proportions of fat (CT fat%), lean (CT lean%), and bone (CT bone%). Data between slaughter groups were standardised relative to a synthetic phantom consisting of Nylon-6. Models were then trained within each dataset using hot carcase weight and DEXA value to predict CT composition, and then validated in the remaining datasets. Results from across-dataset validation tests demonstrated excellent precision for predicting CT fat%, with RMSE and R2 values of 1.32 and 0.89, compared to values of 1.69 and 0.69 for CT lean%, and 0.81 and 0.68 for CT bone% which had less precision. Accuracy across datasets was also robust, with average bias values of 0.66, 0.83, and 0.51 for CT fat%, lean%, and bone%. •The prototype DEXA required calibration over time.•Validation tests showed DEXA had good precision across datasets.•Validation tests showed DEXA had good accuracy across datasets.