Comparison of rankings for lean meat based on results from a CT scanner and a video image analysis system

• VIAScan® primal weights are significantly less than those from the CT scannner in heavier carcases.
• The ranking of the lambs for lean weight between measurement methods across three years was 0.84.
• The results are important for the use of VIAScan® data in the SIL genetic evaluation program.

Coopworth cross lambs born over three years were examined in this study. Differences between two machines; a computer tomography (CT) scanner and a VIAScan® system for the estimation of carcase lean weight in lamb carcases was examined. The CT scanner provided a significantly higher estimate of carcase lean. The rank correlation (0.84) between the CT scanner and the VIAScan® system for the prediction of carcase lean was significant, but there was a different ranking for carcase lean depending on which machine was used. This has important ramifications for the use of VIAScan® data in the New Zealand Sheep Improvement Ltd genetic programme.