Abstract
Scott Technology Ltd. have developed a robotic boning system for use in lamb abattoirs. This system operates at chain speed and makes use of2D x-ray images taken of the carcass to identify cutting lines. The opportunity exists to replace this x-ray system with a dual energy x-ray absorptiometry (DEXA) system which meets robotic image requirements while also enabling the determination of body composition. This study tested a prototype DEXA design that we have developed with the hypothesis that this system could determine body composition at chain speed. 12 Merino lamb carcasses with weights ranging between 14 and 16.3 kg were scanned using the prototype D EXA system to derive an estimate of fat composition. The carcasses were then scanned using Computed Tomography (CT) to determine fat, lean and bone weights which were then expressed as a percentage of carcase weight. Composition of these carcases varied between 9-15.5% for CT fat, 68-72.5% for CT lean, and 16.2 to 20.7% for CT bone. The DEXA estimate of fat composition was then used to predict CT fat, lean, and bone percentage. Our findings supported the hypothesis as the DEXA system was able to predict carcase composition with a precision (R2) of 0.88, 0.34, and 0.60 for predicting the percentage of CT fat, CT lean and CT bone in the carcase. These results demonstrate the capacity of this prototype DEXA system to estimate body composition and lean meat yield in lamb carcasses at abattoir chain speed.